There is no universal pixel size

A 24 px caption can be large on a 240 px GIF and tiny on a 1200 px GIF. Size text relative to the canvas and the intended display. AddTextToGif.net starts at roughly 14% of the shorter image dimension, clamped to 18–72 px. That is a starting point in this tool, not an accessibility guarantee or a rule for every GIF.

A practical workflow

1. Decide where the GIF will appear

Estimate the smallest common display size, not only the full-size preview. A caption that works in a desktop editor may fail in a narrow message thread. Keep the essential sentence short enough to remain readable without shrinking the font.

2. Set the caption size

Start with one or two lines and increase the size until it is easy to scan. Leave space around the edges because some platforms crop previews. If a long word forces the caption against the boundary, shorten the wording rather than compressing the letters.

3. Build contrast for moving backgrounds

  • Use light text with a dark outline when frames alternate between light and dark.
  • Use dark text with a light outline on pale scenes.
  • Move the caption to a visually quiet region when possible.
  • Avoid color pairs that differ mainly by hue but have similar brightness.

The tool's default outline is approximately 9% of the font size. Increase or reduce it according to the animation; an outline should separate letters from the image without filling the counters inside small characters.

4. Preview the entire frame range

Scrub or play through every frame that contains the caption. Check the brightest and darkest moments, fast cuts, faces, and any object that crosses behind the text. A still preview cannot prove that an animated caption remains readable.

5. Test the exported GIF

Open the downloaded file outside the editor and view it near the size used by the destination. Confirm that text stays inside the canvas, the timing is intact, and the outline does not flicker after GIF color quantization.

Worked example

For a 480 × 270 GIF, the shorter dimension is 270 px. Fourteen percent is about 38 px, so a starting size around 36–40 px is sensible for a short caption. Place white text over the lower third with a dark outline, then inspect any frame where a white object passes behind it. If two lines cover the subject, shorten the caption before reducing it below comfortable reading size.

Contrast and accessibility

The WCAG contrast guidance provides useful targets for text, but measuring animated text over changing imagery is more complicated than measuring text on a flat background. Treat sufficient measured contrast as a baseline and still test the actual animation. GIF text embedded in pixels is also unavailable to screen readers, so include the important message as nearby HTML text when publishing on a web page.

Common mistakes

  • Choosing a font size while viewing the GIF zoomed in.
  • Checking only the first frame.
  • Using a thick outline that closes small letter shapes.
  • Placing text over a face or the action viewers need to see.
  • Encoding a paragraph when a short caption would work.

For the complete export workflow, read how to add text without ruining GIF quality and the tool guide.