text-emphasis
CSS property · 8 supported, 0 partial, 9 unsupported across 21 clients
8 of 21 email clients render text-emphasis fully (Sep 2, 2026 data); it breaks outright in Gmail Android, Outlook (New), Outlook Classic and 6 more.
- 3/7 webmail, 2/6 desktop, 3/8 mobile clients support text-emphasis fully.
- Unsupported in Gmail Android, Outlook (New), Outlook Classic, Outlook Android and 5 more.
- Outlook Classic (Word engine, supported to at least 2029) does not fully support text-emphasis, and its replacement changes little here; see the deprecation diff.
- 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 Jul 7, 2022, synced by Emailens Sep 2, 2026.
Client Support
| Client | Category | Engine | Support |
|---|---|---|---|
| Gmail | webmail | Gmail Web | Supported |
| Gmail Android | mobile | Gmail Mobile | Unsupported |
| Gmail iOS | mobile | Gmail Mobile | Supported |
| Outlook 365 | webmail | Outlook Web | Supported |
| Outlook (New) | desktop | Outlook Web | Unsupported |
| Outlook Classic | desktop | Microsoft Word | Unsupported |
| Outlook iOS | mobile | Outlook Mobile | Supported |
| Outlook Android | mobile | Outlook Mobile | Unsupported |
| Outlook for Mac | desktop | WebKit | Supported |
| Apple Mail | desktop | WebKit | Supported |
| Apple Mail iOS | mobile | WebKit | Supported |
| Yahoo Mail | webmail | Yahoo | Unsupported |
| Yahoo Mail Android | mobile | Yahoo | Unsupported |
| Yahoo Mail iOS | mobile | Yahoo | Unsupported |
| Samsung Mail | mobile | Samsung | Unsupported |
| Thunderbird | desktop | Gecko | Unknown |
| HEY Mail | webmail | WebKit | Unknown |
| Proton Mail | webmail | Proton | Supported |
| AOL Mail | webmail | AOL | Unsupported |
| Fastmail | webmail | Fastmail | Unknown |
| Superhuman | desktop | Blink | Unknown |
Client-by-client behaviour for text-emphasis
Fully supports text-emphasis (8): Gmail, Gmail iOS, Outlook 365, Outlook iOS, Outlook for Mac, Apple Mail, Apple Mail iOS, Proton Mail.
No support (9): Gmail Android, Outlook (New), Outlook Classic, Outlook Android, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, Samsung Mail, AOL Mail. Plan fallbacks for these clients before relying on text-emphasis in production sends.
Behaviour unverified in: Thunderbird, HEY Mail, Fastmail, Superhuman.
Fixes & Workarounds
Gmail Android
Unsupported"text-emphasis" is not supported in this email client.
Outlook (New)
Unsupported"text-emphasis" is not supported in this email client.
Outlook Classic
Unsupported"text-emphasis" is not supported in this email client.
Outlook Android
Unsupported"text-emphasis" is not supported in this email client.
Yahoo Mail
Unsupported"text-emphasis" is not supported in this email client.
Yahoo Mail Android
Unsupported"text-emphasis" is not supported in this email client.
Yahoo Mail iOS
Unsupported"text-emphasis" is not supported in this email client.
Samsung Mail
Unsupported"text-emphasis" is not supported in this email client.
AOL Mail
Unsupported"text-emphasis" is not supported in this email client.
Related Features
Check your own HTML for text-emphasis
Paste your own, or run the sample below. Analyzed in this page, with no signup and nothing stored.
Test your text-emphasis layout across 21 email clients
Preview rendering, catch CSS issues, and see how text-emphasis displays across Outlook, Gmail, and Apple Mail. Free, no account needed.
Instant live preview · No signup required · 21 email engines
Last tested upstream: · Last synced by Emailens:
caniemail.com (MIT) records Jul 7, 2022 as the last time text-emphasis 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.