Real FFmpeg
Frame extraction and GIF encoding use the same filters a video editor would, including palette based GIF output.
Free Online Video Tools
Work on video without an upload queue. FFmpeg compiled to WebAssembly reads the file inside your browser, so frames, stills and GIFs are produced on your own device.
Frames and GIF Maker
Browse a video as a filmstrip, save any frame as a full resolution image, or mark a range and export it as a looping GIF.
Open the frame and GIF toolVideo Transitions
Place a cut point on the timeline and blend the two halves with any of the effects in the FFmpeg xfade catalogue, then export a new MP4.
Open the transition toolPhoto Slideshow Maker
Turn a set of pictures into one MP4: drag them into order, set a duration per photo, choose a transition for every join and add music.
Open the slideshow tool
What is inside
How the Video Tools Work
Every step is a real FFmpeg command running in WebAssembly, not a hand written decoder.
| Step | Handled by | Where it runs |
|---|---|---|
| Reading the container | FFmpeg demuxer | WebAssembly in a Web Worker |
| Sampling the filmstrip | FFmpeg fps and select filters | WebAssembly in a Web Worker |
| Saving a still | FFmpeg seek plus one frame output | WebAssembly in a Web Worker |
| Encoding the GIF | FFmpeg palettegen and paletteuse | WebAssembly in a Web Worker |
| Rendering a transition | FFmpeg trim and xfade, plus acrossfade for audio | WebAssembly in a Web Worker |
Privacy: the video is written into the memory file system of the WebAssembly build and processed there. Nothing is uploaded to the 73hi server and nothing is stored after you close the tab.
Why WebAssembly
Desktop Grade Video Filters, No Installation
The same build handles decoding, seeking and GIF palette generation.
Nothing is uploaded
Processing happens in your browser, so large or private clips never travel over the network.
Loaded on demand
The engine only downloads when you open a video tool, and your browser caches it for next time.
Focused pages
Each tool has its own page with instructions, limits and a FAQ, so there is nothing to configure first.
Questions and answers
Video Tools FAQ
Are these video tools free?
Yes. The video tools on 73hi are free to use with no signup and no daily limit.
Is my video uploaded anywhere?
No. FFmpeg compiled to WebAssembly runs in a Web Worker in your browser, so the video, the extracted frames and the GIF never reach the 73hi server.
Why does the first visit download a large file?
The WebAssembly build of FFmpeg is about 31 MB. It is self-hosted, cached by your browser after the first load, and only downloaded when you open a video tool.
Which video formats are supported?
Most common containers and codecs work, including MP4, MOV, WebM, MKV and AVI. Very unusual codecs may need to be converted to MP4 with H.264 first.