Outlook on desktop uses Word's HTML engine. Gmail uses a modern HTML/CSS subset. The gap between the two is the reason every email developer has grey hairs. Our screenshots put them next to each other so you can see the problem fast.
Where Gmail and Outlook most commonly diverge
- Background images on divs — Gmail renders, Outlook strips unless VML is used.
paddingon<td>— Gmail accepts, Outlook partial (use cellpadding).- CSS
float— Gmail renders, Outlook collapses to block. - Web fonts — Gmail supports a curated list, Outlook desktop ignores most.
- Images with
max-width— Gmail fine, Outlook scales incorrectly without hard width. - Animated GIFs — both render first frame only on desktop.
- CSS gradients — neither renders reliably; flat colours or VML.
| Feature | Gmail | Outlook desktop |
|---|---|---|
| Background images on divs | Renders | Strips (use VML) |
| padding on <td> | Renders | Partial (use cellpadding) |
| CSS float | Renders | Collapses to block |
| Web fonts | Curated list supported | Most ignored |
| Images with max-width | Fine | Scales incorrectly without hard width |
| Animated GIFs (desktop) | First frame only | First frame only |
| CSS gradients | Unreliable | Unreliable (use VML) |
Side-by-side in the report
- Gmail webmail screenshot.
- Outlook.com webmail screenshot.
- Outlook desktop rendering (via a rendering worker).
- Click to toggle light/dark; click to toggle mobile/desktop.
Typical fixes after seeing the screenshots
- Switch floats to nested tables.
- Use
<!--[if mso]>conditional HTML for Outlook-specific structure. - Hard-set image widths; don't rely on
max-width. - Avoid background images on containers; use solid colours or bulletproof background patterns.
- Web-safe font stacks with brand fonts as first choice for Gmail, safe fallbacks for Outlook.
Compare rendering for your template
Run a free test. Gmail and Outlook screenshots in the same report. No signup.
FAQ
Do you render Outlook desktop or just Outlook.com?
Both. Outlook desktop rendering is slower (runs in a dedicated worker) but the most important surface for B2B.
What about the new Outlook (Monarch)?
Covered — it's WebView2 based and renders closer to Outlook.com than to Outlook desktop classic. We flag when the rendering differs significantly from classic.
Can I get these screenshots via API?
Yes, in the /api/tests/:token response.
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