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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
Test Your Email Now
Paste your HTML and see how it renders in clients that don't support font-weight.