abox.tools

English

How to edit a GIF frame by frame

There is no GIF editor here, and there does not need to be: a splitter that takes the animation apart into frames, and a maker that builds one from frames, are an editor with a folder in the middle — and the folder is the part where you do the editing, with whatever you already use for images.

Last updated 26 August 2026

View as Markdown

The short answer

  1. Take it apart. Open the GIF Splitter and drop the GIF in. Every frame becomes its own PNG — as it appears on screen, with the transparency kept — and the ZIP includes a timing list, the per-frame delays written down for the rebuild.
  2. Edit the folder. Delete the frames that should go, retouch the ones that should change in any image editor, rename to reorder. A folder of PNGs is a format everything understands.
  3. Put it back together. Drop the folder on the GIF Maker, set the hold times — or lean on the timing list — choose the palette, and export.

All three steps run in your browser. Nothing is uploaded at any point, which matters more than usual here: the GIFs people fix are so often screen recordings with something sensitive half-visible in them.

What the splitter can tell you before you edit

The splitter shows, for every frame, its delay, position, size and disposal — and that panel is worth a look before touching anything, because it explains the two surprises in most GIFs.

First: frames are not all whole pictures. Many GIFs store only the pixels that changed, patched over the frame before — the splitter offers each frame as it appears or as stored, and for editing you almost always want as it appears, so each PNG stands alone. Second: delays are per frame, not one number. The pause on the punchline is a real delay on a real frame, and the timing list is what carries it across the round trip.

For the common cuts, the folder step is optional: keeping every second or fifth frame, or ticking the frames to keep, is built into the splitter itself — halving the frames is the single most effective slimming a GIF can get.

The splitter showing twelve numbered frames of an animation, each with the delay it is held for.
Every frame, numbered, with its own delay. This is the half that tells you what you are editing before you edit it.

What the rebuild costs, honestly

A GIF holds at most 256 colours, chosen when it is built. The rebuild quantises the frames again — one shared palette, or the best colours per frame — and on photographic material that second quantisation can show. On screen recordings and drawings, the usual cargo, it does not: they never used 256 colours to begin with.

The maker's other levers are the ones the GIF budget guide describes: fewer colours, Floyd–Steinberg dithering for gradients, and loop behaviour — forever, once, or a count.

To see whether the surgery worked — and where the bytes actually live — drop the result on the GIF Analyzer: it charts frames against bytes, and the heavy frame is usually a full repaint someone could crop.

The maker offers that trip itself: after the export, a row under its download button carries the fresh GIF straight into the analyzer, already loaded.

The GIF maker with six frames listed in order, each with a delay field, and a row for setting every delay at once.
And back the other way. The delays have to be put back by hand, which is the part of the round trip worth knowing about in advance.

If you do this every week

Split, folder, rebuild — the steps live on separate pages because each does one job, and each can prove on its own that nothing leaves your machine. But all of it is open source: MIT-licensed, one folder per tool, dependency-free ES modules whose READMEs explain the decoder, the disposal rules and the quantiser.

If GIF surgery is a recurring chore, point a coding agent at the repository and ask it to fold the splitter's frame table and the maker's encoder into one page where deleting a frame is one click. The modules were written to be read, and lifting them is what the licence is for.