columns
CSS property · 15 supported, 0 partial, 6 unsupported across 21 clients
15 of 21 email clients render columns fully (Sep 2, 2026 data); it breaks outright in Outlook (New), Outlook Classic, Yahoo Mail and 3 more.
- 5/7 webmail, 4/6 desktop, 6/8 mobile clients support columns fully.
- Unsupported in Outlook (New), Outlook Classic, Yahoo Mail, Yahoo Mail Android and 2 more.
- Outlook Classic (Word engine, supported to at least 2029) does not fully support columns, 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 Aug 2, 2022, synced by Emailens Sep 2, 2026.
Client Support
| Client | Category | Engine | Support |
|---|---|---|---|
| Gmail | webmail | Gmail Web | Supported |
| Gmail Android | mobile | Gmail Mobile | Supported |
| 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 | Supported |
| 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 | Supported |
| Thunderbird | desktop | Gecko | Supported |
| HEY Mail | webmail | WebKit | Supported |
| Proton Mail | webmail | Proton | Supported |
| AOL Mail | webmail | AOL | Unsupported |
| Fastmail | webmail | Fastmail | Supported |
| Superhuman | desktop | Blink | Supported |
Client-by-client behaviour for columns
Fully supports columns (15): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook iOS, Outlook Android, Outlook for Mac, Apple Mail, Apple Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, Fastmail, Superhuman.
No support (6): Outlook (New), Outlook Classic, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail. Plan fallbacks for these clients before relying on columns in production sends.
Fixes & Workarounds
Outlook (New)
Unsupported"columns" is not supported in this email client.
Outlook Classic
Unsupported"columns" is not supported in this email client.
Yahoo Mail
Unsupported"columns" is not supported in this email client.
Yahoo Mail Android
Unsupported"columns" is not supported in this email client.
Yahoo Mail iOS
Unsupported"columns" is not supported in this email client.
AOL Mail
Unsupported"columns" is not supported in this email client.
Related Features
Check your own HTML for columns
Paste your own, or run the sample below. Analyzed in this page, with no signup and nothing stored.
Test your columns layout across 21 email clients
Preview rendering, catch CSS issues, and see how columns 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 Aug 2, 2022 as the last time columns 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.