CSS Properties

word-break

CSS property · 5 supported, 11 partial, 5 unsupported across 21 clients

As of Sep 2, 2026, word-break fails or degrades in 16 of 21 email clients, treat it as progressive enhancement, never structure.

2/7 webmail, 3/6 desktop, 0/8 mobile clients support word-break fully.
Unsupported in Outlook Classic, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS and 1 more.
Partial in Gmail Android, Gmail iOS, Outlook 365, Outlook iOS and 7 more, behavior differs from browsers, test before relying on it.
Outlook Classic (Word engine, supported to at least 2029) does not fully support word-break, one of the few features its replacement actually fixes; see the deprecation diff.
Documented before/after fixes on this page cover 21 clients, including Gmail and Gmail Android.
Across all clients, only 6 of 298 tracked HTML/CSS features render identically everywhere.

Source: caniemail.com (MIT), via the Emailens engine. Last tested upstream Feb 15, 2022, synced by Emailens Sep 2, 2026.

Client Support

Client	Category	Engine	Support
Gmail	webmail	Gmail Web	Supported^{See caveat 1}
Gmail Android	mobile	Gmail Mobile	Partial^{See caveat 2}
Gmail iOS	mobile	Gmail Mobile	Partial^{See caveat 2}
Outlook 365	webmail	Outlook Web	Partial^{See caveat 2}
Outlook (New)	desktop	Outlook Web	Supported
Outlook Classic	desktop	Microsoft Word	Unsupported
Outlook iOS	mobile	Outlook Mobile	Partial^{See caveat 2}
Outlook Android	mobile	Outlook Mobile	Partial^{See caveat 2}
Outlook for Mac	desktop	WebKit	Partial^{See caveat 2}
Apple Mail	desktop	WebKit	Partial^{See caveat 2}
Apple Mail iOS	mobile	WebKit	Partial^{See caveat 2}
Yahoo Mail	webmail	Yahoo	Unsupported
Yahoo Mail Android	mobile	Yahoo	Unsupported
Yahoo Mail iOS	mobile	Yahoo	Unsupported
Samsung Mail	mobile	Samsung	Partial^{See caveat 2}
Thunderbird	desktop	Gecko	Supported
HEY Mail	webmail	WebKit	Partial^{See caveat 3}
Proton Mail	webmail	Proton	Partial^{See caveat 2}
AOL Mail	webmail	AOL	Unsupported
Fastmail	webmail	Fastmail	Supported
Superhuman	desktop	Blink	Supported

Documented caveats (3)

1.Gmail: Supported. But Gmail adds <wbr> every 30 characters.
2.Gmail Android, Gmail iOS, Outlook 365, Outlook iOS, Outlook Android, Outlook for Mac, Apple Mail, Apple Mail iOS, Samsung Mail, Proton Mail: Buggy. Supported but a word-wrap:break-word is applied, making it look like break-all.
3.HEY Mail: Buggy. Every value is replaced by break-word.

Caveats recorded by caniemail.com (MIT) and carried verbatim, one entry per wording rather than per client.

Client-by-client behaviour for word-break

Fully supports word-break (5): Gmail, Outlook (New), Thunderbird, Fastmail, Superhuman.

Partial support (11): Gmail Android, Gmail iOS, Outlook 365, Outlook iOS, Outlook Android, Outlook for Mac, Apple Mail, Apple Mail iOS, Samsung Mail, HEY Mail, Proton Mail. Expect rendering quirks unique to each engine. Partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.

No support (5): Outlook Classic, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail. Plan fallbacks for these clients before relying on word-break in production sends.

Fixes & Workarounds

Outlook Classic

Unsupported

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Yahoo Mail

Unsupported

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Yahoo Mail Android

Unsupported

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Yahoo Mail iOS

Unsupported

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

AOL Mail

Unsupported

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Gmail Android

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Gmail iOS

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Outlook 365

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Outlook iOS

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Outlook Android

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Outlook for Mac

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Apple Mail

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Apple Mail iOS

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Samsung Mail

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

HEY Mail

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Proton Mail

Partial

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width.

Before (Broken)

before.html

3 lines

<span style="word-break: break-all;">
  https://example.com/very/long/url?token=abc123def456
</span>

After (Fixed)

fixed.html

8 lines

<table role="presentation" width="100%" cellpadding="0"
  cellspacing="0" border="0">
  <tr>
    <td width="100%">
      https://example.com/&#8203;very/&#8203;long/&#8203;url?token=&#8203;abc123def456
    </td>
  </tr>
</table>

Outlook Windows does not wrap a URL on word-break, word-wrap, or overflow-wrap. Insert  in a cell that has a width

Production guidance for word-break

word-break is a CSS property. Across the email client matrix, 5 of 21 tracked clients support it fully, 11 only partially, and 5 not at all. The clients most likely to require a workaround for this feature are Outlook Classic, Yahoo Mail, Yahoo Mail Android. Each of them needs a tailored fallback. See the per-client examples above for the specific code fix Emailens recommends.

When in doubt, ship a baseline that renders without word-break and treat it as progressive enhancement on clients where support is verified. Emailens automatically detects cross-client divergence on this feature when you preview an email, so you can see exactly which template paths break before a campaign goes out.

Related Features

!important accent-color align-items animation aspect-ratio backdrop-filter background background-blend-mode

Check your own HTML for word-break

Paste your own, or run the sample below. Analyzed in this page, with no signup and nothing stored.

Zero-Friction Engine Preview

Test your word-break layout across 21 email clients

Preview rendering, catch CSS issues, and see how word-break displays across Outlook, Gmail, and Apple Mail. Free, no account needed.

Instant live preview · No signup required · 21 email engines

Last tested upstream: Feb 15, 2022 · Last synced by Emailens: Sep 2, 2026

caniemail.com (MIT) records Feb 15, 2022 as the last time word-break was tested in a real client, 4 years before this sync. Syncing copies that result forward, it does not re-test it. Carried in @emailens/engine data v0.12.2.