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Does CSS tab-size Work in HTML Email?
Sets the width of tab characters in pre-formatted text.
Quick Answer
Does tab-size work in HTML email?
The CSS tab-size property is supported in Outlook (Mac / Web), Apple Mail, Samsung Email. It is NOT supported in Gmail, Outlook (Windows), Yahoo! Mail. Always include a safe fallback for unsupported clients.
Which Email Clients Support CSS tab-size?
CSS support for tab-size across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✗ No | ✗ No | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✓ Yes | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✗ No | ✗ No | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ? | ? | — |
| ProtonMail | ? | ? | — |
| Fastmail | ? | ? | — |
Notes
- #1 Supports `tab-size` but doesn't support `white-space`. Therefore, `tab-size` is not effectively visible
- #2 Supports `tab-size` but strips the tab character `	`
Frequently Asked Questions
Test Your Email Now
Paste your HTML and see how it renders in clients that don't support tab-size.