Every conversion and compression happens on your own machine, powered by ffmpeg compiled to WebAssembly. No server ever receives your video. Here is exactly what happens when you drop in a file.
When you drop a clip into SimpleGIF, the browser reads it straight into memory on your device. There is no backend, no upload request, and no queue. That is the core difference from most online converters, which send your footage to their servers before they can touch it.
SimpleGIF ships ffmpeg — the same industry-standard media engine used everywhere — compiled to WebAssembly (Wasm). Wasm lets that engine run at near-native speed directly inside your browser tab, using your own CPU. When your browser supports cross-origin isolation, a multithreaded core kicks in and encodes 2–4× faster.
Before encoding you dial in exactly what you want: trim the start and end, set the frame rate (FPS), cap the output width, pick a playback speed from 0.5× to 5×, and choose whether the GIF loops forever. These are the knobs that decide how the GIF looks and how large the file gets.
Encoding shows a live progress bar frame by frame. When it finishes, you preview the GIF looping before committing. Change a setting and re-render immediately — the source file is already in memory, so there is no re-upload and no reload.
The compress tool re-encodes MP4, MOV and WebM videos to smaller H.264 files, up to 500MB, entirely on your device. Pick a quality, optionally downscale, or strip the audio track to shrink the file further — again, with nothing uploaded.
Because your file never leaves the tab, there is no upload size cap, no waiting in a server queue, and no risk of your footage sitting on someone else's machine. It is private by architecture, not by promise. Read more on the privacy policy and why a GIF is often the right format.