:adjacent-sibling
selector or pseudo-class · 10 supported, 2 partial, 2 unsupported across 15 clients
The adjacent sibling combinator (+) selects an element that immediately follows another at the same level. It is supported in modern Apple Mail and webmail clients when <style> blocks survive, and ignored in Outlook for the usual reason. It is most useful for spacing relationships between adjacent content blocks.
Client Support
| Client | Category | Engine | Support |
|---|---|---|---|
| Gmail | webmail | Gmail Web | Supported |
| Gmail Android | mobile | Gmail Mobile | Partial |
| Gmail iOS | mobile | Gmail Mobile | Partial |
| 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 |
| Apple Mail | desktop | WebKit | Supported |
| Apple Mail iOS | mobile | WebKit | Supported |
| Yahoo Mail | webmail | Yahoo | Supported |
| Samsung Mail | mobile | Samsung | Supported |
| Thunderbird | desktop | Gecko | Supported |
| HEY Mail | webmail | WebKit | Supported |
| Superhuman | desktop | Blink | Unknown |
Client-by-client behaviour for :adjacent-sibling
Fully supports :adjacent-sibling (10): Gmail, Outlook 365, Outlook iOS, Outlook Android, Apple Mail, Apple Mail iOS, Yahoo Mail, Samsung Mail, Thunderbird, HEY Mail.
Partial support (2): Gmail Android, Gmail iOS. Expect rendering quirks unique to each engine — partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.
No support (2): Outlook (New), Outlook Classic. Plan fallbacks for these clients before relying on :adjacent-sibling in production sends.
Behaviour unverified in: Superhuman.
When to use :adjacent-sibling in email
- Adding extra top-margin between adjacent paragraphs in long-form content.
- Styling the first heading after an image differently than other headings.
- Creating visual rhythm between sequential card-style sections.
Rendering behaviour and edge cases
- Outlook on Windows ignores adjacent sibling selectors because <style> is stripped.
- Gmail rewrites class names, which can break adjacent-sibling selectors that rely on class matching.
- Apple Mail supports the combinator reliably in recent macOS and iOS releases.
Recommended fallback strategy
Replicate the spacing relationships using explicit inline margin or padded cells for Outlook coverage. Treat adjacent-sibling styling as progressive enhancement.
Fixes & Workarounds
Outlook (New)
Unsupported":adjacent-sibling" is not supported in this email client.
Outlook Classic
Unsupported":adjacent-sibling" is not supported in this email client.
Gmail Android
Partial":adjacent-sibling" is not supported in this email client.
Gmail iOS
Partial":adjacent-sibling" is not supported in this email client.
Related Features
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Try Emailens FreeSupport data last updated Apr 27, 2026 · synced from caniemail.com via @emailens/engine.