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Does CSS font-weight Work in HTML Email?
Sets the weight or thickness of the font, from thin (100) to black (900).
Quick Answer
Does font-weight work in HTML email?
The CSS font-weight property is supported in all major email clients tested. You can use it with confidence in your HTML emails.
Which Email Clients Support CSS font-weight?
CSS support for font-weight across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✓ Yes | ✓ Yes | — |
| Outlook (Windows) | ~ Partial | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✓ Yes | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ~ Partial | ~ Partial | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ✓ Yes | ✓ Yes | — |
| Fastmail | ✓ Yes | ? | — |
Notes
- #1 Partial support. `<number>` values are not supported as per CSS Fonts Level 4 where any `<number>` value between 1 and 1000 (inclusive) is a valid value. Only the following numeric values are supported: 100, 200, 300, 400, 500, 600, 700, 800, and 900.
- #2 Partial support. `<number>` values between 0 and 599 are set as normal font weight. `<number>` values between 600 and 1000 are set as bold font weight.
Frequently Asked Questions
Related CSS Properties
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