Made a free tool for testing video hooks, here's why and how it works

backstory: i make short videos for my app. the format that works for me is a reaction clip with hook text on top, then the app demo. the hook decides most of the result, but you only find the good one by testing a lot of them, and making every version by hand took me hours. so i was testing like 2 hooks a week so i built a tool that takes a few reaction clips, a few app demos and a list of hooks and makes every combination. 3 reactions x 3 hooks x 3 demos gives 27 videos in under a minute. you also get a csv that maps each file to its hook, so when one video does well you know exactly which hook, face and demo it was why it might be useful for you: if you’re doing tiktok or reels for your saas, the bottleneck usually isnt ideas, its making enough versions to actually learn something. this makes the versions free tech stack, since people here usually ask: no backend at all. everything renders in the browser with webcodecs through mediabunny. each source video gets decoded once per batch, frames drawn on canvas, encoded to h264 + aac, then a small zip writer bundles it. nothing gets uploaded, which also means it costs me nothing to run, so it can stay free