Optimize & inspect · Free · No upload

Test and analyze a GIF

The GIF Tester reads a GIF’s internal structure and reports everything about it: GIF87a/89a version, dimensions, frame count, every frame’s stored delay and the delay browsers actually use, total duration and average fps, loop setting, global and local palettes, transparency, interlacing and comments. It then runs checks — damaged file, missing loop, too-fast frames, oversized dimensions — and compares the size with common platform limits.

  • Runs in your browser
  • No sign-up
  • No watermark
  • Works on mobile
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How to use GIF Tester

  1. 01

    Upload a GIF

    Drop any GIF — it’s read, not changed.

  2. 02

    Read the report

    Summary, pass/warning checks and a frame-by-frame table.

  3. 03

    Fix what’s flagged

    Follow the links to the right tool for each issue.

Reading the report

Delay (stored) is what the file says; Plays as is what browsers do — delays under 20 ms become 100 ms. Disposal tells the viewer what to do with a frame before drawing the next: keep it, clear it to the background, or restore the previous image; optimised GIFs mix these with partial-frame regions. Local palettes mean frames carry their own colours, which improves quality at a small size cost.

Warnings link straight to the fix: Fix GIF for damage and timing, the GIF Looper for loop settings, the GIF Resizer for huge dimensions and the GIF compressor for size limits.

Watching the animation frame by frame

The tester describes the GIF; to watch it closely, open it in Pause GIF, which plays, pauses, steps frame by frame and changes playback speed. To export the frames themselves, use the GIF Splitter.

Features

  • Real playback timing

    Shows stored delays and how browsers actually play them.

  • Structure checks

    Detects truncation, missing loops and out-of-bounds frames.

  • Platform limits

    Discord emoji and uploads, X (Twitter) GIF size.

  • Read-only

    Your file isn’t modified or uploaded.

GIF Tester FAQ

How can I check how many frames a GIF has?

Drop it into the GIF Tester. The summary shows the frame count, duration and average fps, and the table lists every frame.

How do I know if a GIF loops?

The Loop row shows “Forever”, a number of repeats, or “Not set (plays once)” when the GIF has no loop setting.

Is my GIF too big for Discord?

The tester checks the file against Discord’s 256 KB emoji limit and 10 MB free upload limit, and X’s 15 MB GIF limit.

Are my files uploaded to a server?

No. GifRush processes everything locally in your browser using JavaScript, Canvas, Web Workers and WebCodecs. Your files never leave your device, and closing the tab discards them.

Fix GIF

Repair broken GIFs: recover truncated files, fix too-fast frames and missing loops.

RepairRecover framesFix speed

Pause GIF

Play, pause and step through any GIF frame by frame, change speed and save any frame.

Play / pauseFrame stepSlow motion

GIF Compressor

Reduce GIF file size with fewer colours, lossy frame diffing, frame dropping and scaling.

LossyColoursFrames

GIF Looper

Make a GIF loop forever, play a set number of times, or once — plus a pause at the end.

Loop foreverLoop countEnd pause

GIF Splitter

Split a GIF into individual PNG frames and download them one by one or as a ZIP.

PNGZIPFrame delays

ANI to GIF

Convert Windows animated cursors (.ani) to animated GIFs with their original timing.

ANICursorsRIFF

MNG to GIF

Convert legacy MNG (Multiple-image Network Graphics) animations to GIF.

MNGLegacyPNG-based

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