883

I made an HTML page that has an <input> tag with type="text". When I click on it using Safari on iPhone, the page becomes larger (auto zoom). Does anybody know how to disable this?

9
  • 11
    For all Twitter Bootstrap users landing here: see also this Github issue.
    – Jeroen
    Mar 8, 2015 at 22:15
  • 83
    I swear, Apple creates these anti-features just to mess with our heads. Aug 24, 2019 at 23:57
  • 12
    @AndrewKoster, I agree with you even now in 2020.
    – Ashok
    Feb 13, 2020 at 11:01
  • 15
    August 2020, and one more time, I got back here, hoping for a miracle in the answers. See your next year. I am going to eat an apple.
    – Marc
    Aug 6, 2020 at 9:31
  • 19
    iOS is next IE.
    – step
    Nov 26, 2020 at 8:26

41 Answers 41

889

You can prevent Safari from automatically zooming in on text fields during user input without disabling the user’s ability to pinch zoom. Just add maximum-scale=1 but leave out the user-scale attribute suggested in other answers.

It is a worthwhile option if you have a form in a layer that “floats” around if zoomed, which can cause important UI elements to move off screen.

<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">

17
  • 73
    This will break android devices zooming ability
    – fen1ksss
    Aug 14, 2018 at 14:52
  • 5
    @daxmacrog, you are right, but the OP did not mention whether he wants to break androids by allowing needed behaviour. This is where personally I took incorrect option. Of course, it's better to specify.
    – fen1ksss
    Aug 15, 2018 at 11:27
  • 40
    @HenrikPetterson This does more than just disabling the auto-zoom as specified by OP, it also disables pinch zoom. So I don't think it's the 2018+ solution. Sep 17, 2018 at 23:05
  • 6
    @AndréWerlang That is not accurate. As stated clearly in the answer, this solution does not disable pinch zoom in Safari (or Firefox), which is what the OP asked about. But as pointed out in previous comments, it does disable user zoom on Android devices and in Chrome on iOS.
    – daxmacrog
    Sep 18, 2018 at 0:07
  • 20
    There's a lot of confusion about whether maximum-scale=1 annoyingly disables user pinch zoom. The behavior changed with iOS 10 when Apple rightly decided to ignore disabling user pinch zoom. The good news is that the setting still works to prevent automatic zoom on focus. Oct 27, 2019 at 8:54
665

The browser will zoom if the font-size is less than 16px and the default font-size for form elements is 11px (at least in Chrome and Safari).

Additionally, the select element needs to have the focus pseudo-class attached.

input[type="color"],
input[type="date"],
input[type="datetime"],
input[type="datetime-local"],
input[type="email"],
input[type="month"],
input[type="number"],
input[type="password"],
input[type="search"],
input[type="tel"],
input[type="text"],
input[type="time"],
input[type="url"],
input[type="week"],
select:focus,
textarea {
  font-size: 16px;
}

It's not necessary to use all the above, you can just style the elements you need, eg: just text, number, and textarea:

input[type='text'],
input[type='number'],
textarea {
  font-size: 16px;
}

Alternate solution to have the input elements inherit from a parent style:

body {
  font-size: 16px;
}
input[type="text"] {
  font-size: inherit;
}
27
  • 87
    Just to get everything covered: select, textarea, input[type="text"], input[type="password"], input[type="datetime"], input[type="datetime-local"], input[type="date"], input[type="month"], input[type="time"], input[type="week"], input[type="number"], input[type="email"], input[type="url"], input[type="search"], input[type="tel"], input[type="color"] { font-size: 16px; } Jul 5, 2013 at 15:10
  • 8
    @Nic You need to use select:focus. Was having the same issue too.
    – DGibbs
    Jun 9, 2014 at 14:25
  • 226
    I don't understand, how is this a fix? What if I want a smaller/larger font size?
    – bryan
    Aug 3, 2015 at 23:46
  • 55
    proper way is to change meta tag to: <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"/> Dec 4, 2015 at 9:57
  • 52
    @MilosMatic In most cases probably not a good solution, as it completely prevents the user from scaling the page. Potentially even more annoying for your visitors.
    – BadHorsie
    Jul 8, 2016 at 14:32
266
@media screen and (-webkit-min-device-pixel-ratio:0) { 
  select:focus,
  textarea:focus,
  input:focus {
    font-size: 16px;
    background: #eee;
  }
}

New: IOS will still zoom, unless you use 16px on the input without the focus.

@media screen and (-webkit-min-device-pixel-ratio:0) { 
  select,
  textarea,
  input {
    font-size: 16px;
  }
}

I added a background since IOS adds no background on the select.

16
  • 11
    This works not only for safari on iOS (iphone/ipad/ipod), but also Safari/OSX and Chrome (windows and Mac). So if you're trying to specifically target the iphone, this will not work.
    – Redtopia
    Oct 16, 2013 at 23:13
  • 47
    Why is everyone saying 16px but no one cares to mention why exactly is it 16px? Why such an arbitrary number? Why do we have to set our form field text size to 16px and not .. say 1.8rem or 2.5em or such? Is this just a stupid bug from a proprietary OS?
    – Beebee
    Jul 14, 2015 at 15:30
  • 16
    @Beebee 100% font size is 16px, that the default for most if not all browsers (desktop too). IOS uses it that as the default probably because it's a comfortable size for reading. Why it is set this way I haven't bothered to look up, don't care.
    – Christina
    Jul 14, 2015 at 19:29
  • 7
    Use @media screen and (-webkit-min-device-pixel-ratio:0) and (max-device-width:1024px) to limit the effect to iPhone, but do not modify websites when viewed in Chrome.
    – BurninLeo
    Nov 16, 2015 at 20:17
  • 13
    Instead of using a media query, you should use @supports (-webkit-overflow-scrolling: touch), as this css feature only exists on iOS Jun 26, 2018 at 10:32
228

If your website is properly designed for a mobile device you could decide not allow scaling.

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0" />

This solves the problem that your mobile page or form is going to 'float' around.

18
  • 153
    Technically correct, but I disagree with the reasoning. Disabling user zooms on a properly designed site is generally still a bad idea.
    – Fer
    Feb 4, 2013 at 17:59
  • 27
    "Properly designed" is very subjective. Consider a fixed, 50px header at the top of a site that is fully responsive and should work in all browsers. Zooming in iOS Safari breaks the header positioning and pretty much breaks the whole site.
    – Redtopia
    Oct 15, 2013 at 20:20
  • 71
    Disabling user zoom capability is a terrible practice from a UX perspective and should really be avoided at all costs. Being able to zoom in freely is a basic accessibility feature, and a control that you should never take away from the user. Jan 21, 2014 at 22:58
  • 88
    In native mobile apps you never get the chance to zoom and they work just fine, why would a webapp be any different? If you set the appropriate font-size and line-height with clear contrasts you should be ok.
    – jotav
    Sep 4, 2014 at 13:59
  • 53
    Those using the 'it's fine in native apps' argument are overlooking the fact that well-made native apps adhere to OS-level accessibility settings such as text size. Older and badly sighted users can and do use extremely large OS-wide font sizes because they need to. Web apps often don't or can't adhere to this setting, therefore allowing the web-browser's built-in accessibility functionality such as zooming is vital. Whatever you think is perfectly readable, believe me, there are people who won't find it clear enough. Do not take this option away from users if you value usability. Jun 29, 2015 at 13:13
112

Proper way to fix this issue is to change meta viewport to:

<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"/>

Important: do not set minimum-scale! This keeps the page manually zoomable.

10
  • 58
    This is not necessarily the "proper" way to prevent this behaviour. Mobile Safari zooms in if the text is deemed too small to read. Switching off zooming all together is heavy handed and prevents users from being able to interact with your page in a way that they may expect.
    – Alec Rust
    Jan 20, 2016 at 22:41
  • 8
    Apparently in iOS10 Apple changed the maximum-scale property to not be respected anymore, allowing all sites to zoom in regardless of its setting.
    – Wolfr
    Jun 14, 2016 at 20:09
  • 4
    This works for iOS10 20/September/2016 version... at least works on my app... Thanks!!! Before I was using <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1"> But I switched it to the line on the response and it worked...
    – eljamz
    Sep 22, 2016 at 15:20
  • 4
    "Ensure that the browser pinch zoom is not blocked by the page's viewport meta element so that it can be used to zoom the page to 200%. Restrictive values for user-scalable and maximum-scale attributes of this meta element should be avoided." w3.org/TR/mobile-accessibility-mapping/#zoom-magnification Oct 16, 2016 at 21:24
  • 1
    this worked in ios but in android the pich zoom is not working
    – Pein
    Aug 30, 2018 at 15:24
103

In summary the answer is: set the font size of the form elements to at least 16px

3
  • Yes, this is definetly the best practice to avoid zooming on mobile devices. No js, no hacks, no workarounds at all. But even with 16px I noticed a very little zoom in my pages so I tried 17px, 18px... to see what happens.
    – ed1nh0
    Mar 5, 2013 at 17:22
  • 9
    It is best practice to declare 100% on body, button, input, textarea and select elements. This allows the user to set a default that is not the 16px shipped with browsers. Someone who has trouble reading on screen might set their default to 18px or 20px. You don't want to override their choice by forcing 16px on them. When it comes to iOS, though, they made a decision to scale up any value that their HIG says is too small. Unfortunately it looks like it does not interpret the 100% value, so we are stuck adding in the default to appease it.
    – J. Hogue
    Oct 18, 2016 at 18:43
  • RE iOS Safari, as of this comment it appears Safari correctly interprets the font-size: 100% value and grabs the 16px necessary. Oct 26, 2018 at 19:28
71

As many other answers have already pointed out, this can be achieved by adding maximum-scale to the meta viewport tag. However, this has the negative consequence of disabling user zoom on Android devices. (It does not disable user zoom on iOS devices since v10.)

We can use JavaScript to dynamically add maximum-scale to the meta viewport when the device is iOS. This achieves the best of both worlds: we allow the user to zoom and prevent iOS from zooming into text fields on focus.

| maximum-scale             | iOS: can zoom | iOS: no text field zoom | Android: can zoom |
| ------------------------- | ------------- | ----------------------- | ----------------- |
| yes                       | yes           | yes                     | no                |
| no                        | yes           | no                      | yes               |
| yes on iOS, no on Android | yes           | yes                     | yes               |

Code:

const addMaximumScaleToMetaViewport = () => {
  const el = document.querySelector('meta[name=viewport]');

  if (el !== null) {
    let content = el.getAttribute('content');
    let re = /maximum\-scale=[0-9\.]+/g;

    if (re.test(content)) {
        content = content.replace(re, 'maximum-scale=1.0');
    } else {
        content = [content, 'maximum-scale=1.0'].join(', ')
    }

    el.setAttribute('content', content);
  }
};

const disableIosTextFieldZoom = addMaximumScaleToMetaViewport;

// https://stackoverflow.com/questions/9038625/detect-if-device-is-ios/9039885#9039885
const checkIsIOS = () =>
  /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;

if (checkIsIOS()) {
  disableIosTextFieldZoom();
}
6
  • why you create a copy of addMaximumScaleToMetaViewport? Is it solely for semantic reasons? Sep 18, 2019 at 10:24
  • Yes, just mapping the function to a different name so it's clear how it's being used. Sep 18, 2019 at 14:03
  • 6
    Best solution as of today in 2021 (with a bit arranged code)
    – Crocsx
    May 11, 2021 at 4:22
  • 1
    Continues to be the best solution in 2023!
    – btown
    Jan 28, 2023 at 20:00
  • No way, it works!
    – bora89
    Jun 2, 2023 at 14:14
39
input[type='text'],textarea {font-size:1em;}
6
  • 3
    Note that setting user-scalable to no will disable all zooming, which is probably a bad idea. Sep 23, 2010 at 22:14
  • 20
    This only works if your body font size is the default (un-specified, or 1em, or 100%). If you set a custom font size, you can set the font-size in your snippet to 16px to avoid auto-zooming.
    – Alan H.
    Jun 1, 2011 at 22:08
  • I know this question was directed at iPhone but this is more compatible across platforms and into the future of more platforms/devices, I tried the 16px approach but on an Android tablet only reduced the auto zooming effect. Setting to '1em' as specified in the post solved the issue.
    – toddles_fp
    Sep 15, 2013 at 12:20
  • I had a custom font-size (15px), and setting the font-size to 1rem (not em) worked. Nov 6, 2016 at 16:21
  • 6
    Neither 1em nor 1rem is a proper solution because both can be less than 16px and Safari requires at least 16px to not zoom.
    – Finesse
    Apr 30, 2019 at 2:33
20

Instead of simply setting the font size to 16px, you can:

  1. Style the input field so that it is larger than its intended size, allowing the logical font size to be set to 16px.
  2. Use the scale() CSS transform and negative margins to shrink the input field down to the correct size.

For example, suppose your input field is originally styled with:

input[type="text"] {
    border-radius: 5px;
    font-size: 12px;
    line-height: 20px;
    padding: 5px;
    width: 100%;
}

If you enlarge the field by increasing all dimensions by 16 / 12 = 133.33%, then reduce using scale() by 12 / 16 = 75%, the input field will have the correct visual size (and font size), and there will be no zoom on focus.

As scale() only affects the visual size, you will also need to add negative margins to reduce the field's logical size.

With this CSS:

input[type="text"] {
    /* enlarge by 16/12 = 133.33% */
    border-radius: 6.666666667px;
    font-size: 16px;
    line-height: 26.666666667px;
    padding: 6.666666667px;
    width: 133.333333333%;

    /* scale down by 12/16 = 75% */
    transform: scale(0.75);
    transform-origin: left top;

    /* remove extra white space */
    margin-bottom: -10px;
    margin-right: -33.333333333%;
}

the input field will have a logical font size of 16px while appearing to have 12px text.

I have a blog post where I go into slightly more detail, and have this example as viewable HTML:
No input zoom in Safari on iPhone, the pixel perfect way

0
18

Inspired by @jirikuchta 's answer, I solved this problem by adding this bit of CSS:

#myTextArea:active {
  font-size: 16px; /* `16px` is safer I assume, although `1rem` works too */
}

No JS, and I don't notice any flash or anything.

It's worth noting that a viewport with maximum-scale=1 also works, but not when the page is loaded as an iframe, or if you have some other script modifying the viewport, etc.

17

There's no clean way I could find, but here's a hack...

1) I noticed that the mouseover event happens prior to the zoom, but the zoom happens before mousedown or focus events.

2) You can dynamically change the META viewport tag using javascript (see Enable/disable zoom on iPhone safari with Javascript?)

So, try this (shown in jquery for compactness):

$("input[type=text], textarea").mouseover(zoomDisable).mousedown(zoomEnable);
function zoomDisable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="user-scalable=0" />');
}
function zoomEnable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="user-scalable=1" />');
}

This is definitely a hack... there may be situations where mouseover/down don't always catch entries/exits, but it worked well in my tests and is a solid start.

1
  • 6
    Not sure when Safari behavior might have changed, but now (iOS6.0.1) mousedown is happening prior to the autozoom. Thus in my prior solution, zooming is getting re-enabled too soon. I haven't come up with an adequate fix, since all events I tried now happen before zoom. You could re-enable zoom upon a keydown or blur, but there are some scenarios that this might miss (such as if user wants to manually zoom before they start typing anything).
    – dlo
    Feb 1, 2013 at 22:15
16

This worked for me on iOS Safari and Chrome. For the input selector could be set the class or id to enclose the current.

@supports (-webkit-overflow-scrolling: touch) {
   input {
     font-size: 16px;
   }
}
2
  • 1
    It helps, but how?)
    – Fikret
    Jun 11, 2021 at 10:34
  • Also worked for me. I just pasted this in index.css and boom, no more janky ios zoom.
    – FBB
    Jul 28, 2022 at 19:59
14

I recently (today :D) had to integrate this behavior. In order to not impact the original design fields, including combo, I opted to apply the transformation at the focus of the field:

input[type="text"]:focus, input[type="password"]:focus,
textarea:focus, select:focus {
  font-size: 16px;
}
3
  • FYI, This worked well on my iphone 5 with iOS 6, but on an iphone 4 with iOS 5 in portrait mode, the focus styling was applied after the zoom occurred. Maybe something subtle going on, I didn't investigate further.
    – Vish
    Apr 13, 2013 at 3:20
  • I just want to say I have lots of different queries using zoom to make development go faster and depending on how much you zoom will determine how much font-size you need I believe
    – mike
    May 2, 2014 at 23:59
  • :focus did not work for me iOS 10.2 iPhone 6, but input[type="text"]:hover worked well. Feb 19, 2017 at 20:54
13

Add user-scalable=0 to viewport meta as following

<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=0">

Worked for me :)

3
  • 16
    "Ensure that the browser pinch zoom is not blocked by the page's viewport meta element so that it can be used to zoom the page to 200%. Restrictive values for user-scalable and maximum-scale attributes of this meta element should be avoided." w3.org/TR/mobile-accessibility-mapping/#zoom-magnification Oct 16, 2016 at 21:24
  • 12
    This breaks the rules of accessibility defined by W3. Dec 12, 2016 at 5:57
  • worked for me, also this is the best solution for me as I want the freedom to change input font sizes below 16px and don't want a JS hack
    – Blue Bot
    Oct 21, 2018 at 9:08
10

I have looked through multiple answers.\

  1. The answer with setting maximum-scale=1 in meta tag works fine on iOS devices but disables the pinch to zoom functionality on Android devices.
  2. The one with setting font-size: 16px; onfocus is too hacky for me.

So I wrote a JS function to dynamically change meta tag.

var iOS = navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform);
if (iOS)
    document.head.querySelector('meta[name="viewport"]').content = "width=device-width, initial-scale=1, maximum-scale=1";
else
    document.head.querySelector('meta[name="viewport"]').content = "width=device-width, initial-scale=1";
9

2021 solution...

OK, I've read through all the old answers but none of them worked for me. After many hours of trying different things the solution seemed simple in the end.

input{
    transform: scale(0.875);
    transform-origin: left center;
    margin-right: -14.28%;
}

Tested on iOS/Android/Chrome on PC

This allows you to use a 14px font, if you need a different size then the scaling factor is 14/16 = 0.875 and the negative margin is (1 - 0.875) / 0.875 * 100

My input has a parent set to "display:flex" and it grows to fit the parent because it has "flex: 1 1 auto". You may or may not need this but I'm including it for completeness.

8

Javascript hack which is working on iOS 7. This is based on @dlo 's answer but mouseover and mouseout events are replaced by touchstart and touchend events. Basicly this script add a half second timeout before the zoom would enabled again to prevent zooming.

$("input[type=text], textarea").on({ 'touchstart' : function() {
    zoomDisable();
}});
$("input[type=text], textarea").on({ 'touchend' : function() {
    setTimeout(zoomEnable, 500);
}});

function zoomDisable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=0" />');
}
function zoomEnable(){
  $('head meta[name=viewport]').remove();
  $('head').prepend('<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=1" />');
} 
2
  • This worked best for me. But, I changed the touchstart/touchend events to one 'focus' event with both zoomDisable and zoomEnable. Nov 11, 2013 at 19:52
  • Adding the delay does seem to work pretty well on newer versions of iOS, but it's interesting that it doesn't work very well when set to 250ms. That hints that under some circumstances, 500ms might not work either, but if it works most of the time I guess it's better than not working at all. Good thinking.
    – dlo
    Jan 26, 2015 at 3:44
8

This worked for me:

input, textarea {
    font-size: initial;
}
2
  • Nicely simple, but is there any way to control what that "initial" size is?
    – 2540625
    Sep 15, 2014 at 0:35
  • I haven't tested it, but this should be a way to control the font size. (please let me know if this works and I'll update my answer) body { font-size: 20px; } input { font-size: inherit; }
    – user1000952
    Sep 16, 2014 at 1:19
8

I used Christina's solution above, but with a small modification for bootstrap and another rule to apply to desktop computers. Bootstrap's default font-size is 14px which causes the zoom. The following changes it to 16px for "form controls" in Bootstrap, preventing the zoom.

@media screen and (-webkit-min-device-pixel-ratio:0) {
  .form-control {
    font-size: 16px;
  }
}

And back to 14px for non-mobile browsers.

@media (min-width: 768px) {
  .form-control {
    font-size: 14px;
  }
}

I tried using .form-control:focus, which left it at 14px except on focus which changed it to 16px and it did not fix the zoom problem with iOS8. At least on my iPhone using iOS8, the font-size has to be 16px before focus for the iPhone to not zoom the page.

0
7

I did this, also with jQuery:

$('input[type=search]').on('focus', function(){
  // replace CSS font-size with 16px to disable auto zoom on iOS
  $(this).data('fontSize', $(this).css('font-size')).css('font-size', '16px');
}).on('blur', function(){
  // put back the CSS font-size
  $(this).css('font-size', $(this).data('fontSize'));
});

Of course, some other elements in the interface may have to be adapted if this 16px font-size breaks the design.

3
  • 4
    This is classy. This is stylin'. I'm out of puns. Clever approach.
    – crowjonah
    Jul 26, 2013 at 13:17
  • @Wolfr did you try on an actual device? Jun 24, 2016 at 21:52
  • 1
    This worked for us on iOS 12. I like this approach the best instead of mucking around with css transforms and negative margins. Sep 19, 2019 at 10:04
7

After a while of while trying I came up with this solution

// set font-size to 16px to prevent zoom 
input.addEventListener("mousedown", function (e) {
  e.target.style.fontSize = "16px";
});

// change font-size back to its initial value so the design will not break
input.addEventListener("focus", function (e) {
  e.target.style.fontSize = "";
});

On "mousedown" it sets font-size of input to 16px. This will prevent the zooming. On focus event it changes font-size back to initial value.

Unlike solutions posted before, this will let you set the font-size of the input to whatever you want.

1
  • This one actually works for me, especially since in newer iOS versions you can't use the viewport meta tag to disable zooming.
    – mparizeau
    Feb 5, 2018 at 21:24
7

Pseudo elements like :focus don't work as they used to. From iOS 11, a simple reset declaration can be added before your main styles (providing you don't override them with a smaller font size).

/* Prevent zoom */
select, input, textarea {
  font-size: 16px;
}

It's worth mentioning that for CSS libraries such as Tachyons.css then it's easy to accidentally override your font size.

For example class: f5 is equivalent to: fontSize: 1rem, which is fine if you have kept the body font scale at the default.

However: if you choose font size class: f6 this will be equivalent to fontSize: .875rem on a small display upwards. In that instance you'll need to be more specific about your reset declarations:


  /* Prevent zoom */
  select, input, textarea {
    font-size: 16px!important;
  }

@media screen and (min-width: 30em) {

/* not small */

}

6

After reading almost every single line here and testing the various solutions, this is, thanks to all who shared their solutions, what I came up with, tested and working for me on iPhone 7 iOS 10.x :

@media screen and (-webkit-min-device-pixel-ratio:0) {
    input[type="email"]:hover,
    input[type="number"]:hover,
    input[type="search"]:hover,
    input[type="text"]:hover,
    input[type="tel"]:hover,
    input[type="url"]:hover,
    input[type="password"]:hover,
    textarea:hover,
    select:hover{font-size: initial;}
}
@media (min-width: 768px) {
    input[type="email"]:hover,
    input[type="number"]:hover,
    input[type="search"]:hover,
    input[type="text"]:hover,
    input[type="tel"]:hover,
    input[type="url"]:hover,
    input[type="password"]:hover,
    textarea:hover,
    select:hover{font-size: inherit;}
}

It has some cons, though, noticeably a "jump" as result of the quick font size change occuring between the "hover"ed and "focus"ed states - and the redraw impact on performance

1
  • Thanks you for your feedback, @MikeBoutin . Can you please share your env (device/iOS version)?
    – l3bel
    Mar 18, 2019 at 20:01
6

Using (hover: none) and (pointer: coarse) to target all touchscreen devices:

A number of answers here resort to deploying JavaScript or jQuery.

But it ought to be (and it is) entirely possible to control concerns like conditional font-presentation with CSS.


Safari Mobile requires (with good reason) that any form element, when being interacted with, must have a minimum font-size of 16px (or the visual equivalent).

Let's commit to making that well-thought-out UX apply to all touchscreen browsers.

Then we can adopt the following:

@media only screen and (hover: none) and (pointer: coarse) {

  input,
  select,
  textarea {
    font-size: 11px;
  }

  input:focus,
  select:focus,
  textarea:focus {
    font-size: 16px;
  }
}

The Result

When using a touchscreen device, when any of the interactive form elements above are focused on, the font-size of that form element is temporarily set to 16px.

This, in turn, disables iOS Safari Mobile auto-zoom.

User-initated pinch-zoom remains unaffected on all devices and is never disabled.

4

I've had to "fix" the auto zoom into form controls issue for a Dutch University website (which used 15px in form controls). I came up with the following set of requirements:

  • user must still be able zoom in
  • font-size must remain the same
  • no flashes of temporary different styling
  • no jQuery requirement
  • must work on newest iOS and not hinder any other OS/device combination
  • if possible no magic timeouts, and if needed correctly clear timers

This is what I came up with so far:

/*
NOTE: This code overrides the viewport settings, an improvement would be
      to take the original value and only add or change the user-scalable value
*/

// optionally only activate for iOS (done because I havn't tested the effect under other OS/devices combinations such as Android)
var iOS = navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform)
if (iOS)
  preventZoomOnFocus();


function preventZoomOnFocus()
{
  document.documentElement.addEventListener("touchstart", onTouchStart);
  document.documentElement.addEventListener("focusin", onFocusIn);
}


let dont_disable_for = ["checkbox", "radio", "file", "button", "image", "submit", "reset", "hidden"];
//let disable_for = ["text", "search", "password", "email", "tel", "url", "number", "date", "datetime-local", "month", "year", "color"];


function onTouchStart(evt)
{
  let tn = evt.target.tagName;

  // No need to do anything if the initial target isn't a known element
  // which will cause a zoom upon receiving focus
  if (    tn != "SELECT"
      &&  tn != "TEXTAREA"
      && (tn != "INPUT" || dont_disable_for.indexOf(evt.target.getAttribute("type")) > -1)
     )
    return;

  // disable zoom
  setViewport("width=device-width, initial-scale=1.0, user-scalable=0");
}

// NOTE: for now assuming this focusIn is caused by user interaction
function onFocusIn(evt)
{
  // reenable zoom
  setViewport("width=device-width, initial-scale=1.0, user-scalable=1");
}

// add or update the <meta name="viewport"> element
function setViewport(newvalue)
{
  let vpnode = document.documentElement.querySelector('head meta[name="viewport"]');
  if (vpnode)
    vpnode.setAttribute("content",newvalue);
  else
  {
    vpnode = document.createElement("meta");
    vpnode.setAttribute("name", "viewport");
    vpnode.setAttribute("content", newvalue);
  }
}

Some notes:

  • Note that so far I've only tested it on iOS 11.3.1, but will test it on a few other versions soon
  • Use of focusIn events means it requires at least iOS 5.1 (but I see sites we build working in iOS versions older as 9 as a cool bonus anyway)
  • Using event-delegation because a lot of sites I work on have pages which might dynamically create form controls
  • Setting the eventListeners to the html element (documentElement) so as not having to wait for body to become available (don't want to bother checking if document has ready/loaded state or needing to wait for the DOMContentLoaded event)
1
  • This doesn't work entirely perfect for me (input zoom is triggered for an <input> that is dynamically added when the user pressed a button), but it worked for 85% of my cases, which is good enough at the moment. Just wanted to thank you for sharing your solution!
    – Sven
    Jan 25, 2021 at 10:46
4

Even with these answers it took me three days to figure out what was going on and I may need the solution again in the future.

My situation was slightly different from the one described.

In mine, I had some contenteditable text in a div on the page. When the user clicked on a DIFFERENT div, a button of sorts, I automatically selected some text in the contenteditable div (a selection range that had previously been saved and cleared), ran a rich text execCommand on that selection, and cleared it again.

This enabled me to invisibly change text colors based on user interactions with color divs elsewhere on the page, while keeping the selection normally hidden to let them see the colors in the proper context.

Well, on iPad's Safari, clicking the color div resulted in the on-screen keyboard coming up, and nothing I did would prevent it.

I finally figured out how the iPad's doing this.

It listens for a touchstart and touchend sequence that triggers a selection of editable text.

When that combination happens, it shows the on-screen keyboard.

Actually, it does a dolly zoom where it expands the underlying page while zooming in on the editable text. It took me a day just to understand what I was seeing.

So the solution I used was to intercept both touchstart and touchend on those particular color divs. In both handlers I stop propagation and bubbling and return false. But in the touchend event I trigger the same behavior that click triggered.

So, before, Safari was triggering what I think was "touchstart", "mousedown", "touchend", "mouseup", "click", and because of my code, a text selection, in that order.

The new sequence because of the intercepts is simply the text selection. Everything else gets intercepted before Safari can process it and do its keyboard stuff. The touchstart and touchend intercepts prevent the mouse events from triggering as well, and in context this is totally fine.

I don't know an easier way to describe this but I think it's important to have it here because I found this thread within an hour of first encountering the issue.

I'm 98% sure the same fix will work with input boxes and anything else. Intercept the touch events and process them separately without letting them propagate or bubble, and consider doing any selections after a tiny timeout just to make sure Safari doesn't recognize the sequence as the keyboard trigger.

1
  • This is a great explanation of what safari is doing. Thanks!
    – Jeremy
    Sep 12, 2019 at 20:12
3

In Angular you can use directives to prevent zooming on focus on IOS devices. No meta tag to preserve accessibility.

import { Directive, ElementRef, HostListener } from '@angular/core';

const MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX = 16;

@Directive({ selector: '[noZoomiOS]' })

export class NoZoomiOSDirective {
  constructor(private el: ElementRef) {}

@HostListener('focus')
  onFocus() {
    this.setFontSize('');
  }

@HostListener('mousedown')
  onMouseDown() {
    this.setFontSize(`${MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX}px`);
  }

private setFontSize(size: string) {
  const { fontSize: currentInputFontSize } = window.getComputedStyle(this.el.nativeElement, null);

  if (MINIMAL_FONT_SIZE_BEFORE_ZOOMING_IN_PX <= +currentInputFontSize.match(/\d+/)) {
      return;
   }

  const iOS = navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform);
  iOS 
     && (this.el.nativeElement.style.fontSize = size);
 }
}

You can use it like this <input noZoomiOS > after you declare it in your *.module.ts

0
3

Amazing, there are dozens of answers here with javascript and viewports, and only one other mentions text-size-adjust which is what I believe is the best solution.

You can just set this to none.

Add the following CSS:

* {
 -webkit-text-size-adjust: none;
  text-size-adjust: none;
}
7
  • this doesn't appear to work on ios, is there more to applying to solution successfully--meaning other requirements such as the meta viewport with appropriate values?
    – jimmont
    Oct 21, 2020 at 8:07
  • 7
    Unfortunately this didn't work for me on safari iOS 14.4 Mar 9, 2021 at 22:24
  • According to developer.mozilla.org text-size-adjust is still considered experimental but supported by current mobile Chrome and Safari. As always, check caniuse.com.
    – rocky
    Dec 3, 2021 at 21:29
  • Does this CSS property even have anything to do with auto-zoom? It is meant to control rendered font-size, not screen zoom. Apr 2, 2022 at 8:07
  • @adam Yes it does. It increases the font size for input boxes and that results in auto zoom. Apr 2, 2022 at 19:53
2

Based on Stephen Walsh's answer... This code works without changing the font size of inputs on focus (which looks lame), plus it still works with FastClick, which I suggest adding to all mobile sites to help bring the "snappy". Adjust your "viewport width" to suit your needs.

// disable autozoom when input is focused
    var $viewportMeta = $('head > meta[name="viewport"]');
    $('input, select, textarea').bind('touchend', function(event) {
        $viewportMeta.attr('content', 'width=640, user-scalable=0');
        setTimeout(function(){ $viewportMeta.attr('content', 'width=640, user-scalable=1'); }, 1)
    });
2
  • If the user had already zoomed in a bit before clicking the input control, would this solution cause the viewport to suddenly "unzoom"? Apr 21, 2015 at 22:13
  • Yes it does, but it doesn't look any more jarring than the previous "zoom" effect that happened every time the user clicked on an input.
    – Pete
    Nov 11, 2015 at 18:29
2

I see people here do some strange stuff with JavaScript or the viewport function and turning off all manually zooming on devices. That shouldn't be a solution in my opinion. Adding this CSS snippet will turn off the auto-zoom in iOS without changing your font-size to a fixed number like 16px.

By default, I use 93.8% (15px) font-size at input fields and by adding my CSS snippet this stays at 93.8%. No need to change to 16px or make it a fixed number.

input[type="text"]:focus,
textarea:focus {
    -webkit-text-size-adjust: 100%;
}
1
  • 5
    This doesn’t work for me, tested with both latest iOS 6 and iOS 9.2.1. Here’s a minimal reproducible page: pastebin.com/bh5Zhe9h It still zooms on focus. Strange that this was posted in 2015 and upvoted yet doesn’t work in iOS 6. Feb 15, 2016 at 14:36

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