Email signature GIF size: dimensions and file size that work.

Most email signatures, including the logo and contact lines, are between 300 and 600 px wide. A handwritten signature looks right at 200 to 300 px wide on screen, with a height to match its shape; for a typical wide signature that’s 60 to 120 px tall.

Phones, most laptops and many monitors have high-resolution screens that show two device pixels per CSS pixel. A GIF shown at exactly its own width looks soft on them. Export it at twice the width you show it, then set the display width in your email app.

• Shown at 240 px: export 480 px wide.
• Shown at 400 px, in a wide layout or newsletter: export 800 px.
• Hero images in marketing emails: 1200 px.

There’s no hard limit, but every email you send carries the signature, and people open email on phones over mobile data. Aim for under 500 KB, and treat 1 MB as the ceiling. Larger GIFs load slowly, can push replies toward attachment limits in long threads, and look like heavy marketing mail.

• Pixel area: doubling the width roughly quadruples the pixels in every frame.
• Frame count: a GIF stores every frame. At 25 frames per second, a four-second reveal with a one-second hold is 125 frames.
• Soft gradients: glows and metallic gradients use many colors, and GIF holds only 256, so it dithers them into noisy pixels that compress badly.
• Empty space: a canvas much larger than the signature still costs bytes in every frame.

1. Export the 480 px width for email; the larger widths are for big layouts.
2. Shorten the reveal. A brisk two to three seconds reads well in an inbox.
3. Shorten the hold at the end. The loop starts over anyway.
4. Pick a look without glow, such as Ink on Paper or Classic White. Flat ink makes far smaller GIFs than a halo.
5. On colored email templates, use a transparent GIF so you don’t need a background box, and keep the canvas tight around the signature.

A loop means anyone who opens the email late still sees the writing. Make sure the finished signature holds long enough to be read before it starts again: a second and a half is about right. If animation feels too busy for formal email, use a still PNG of the final frame instead; Everstroke’s email export includes both.