Video Tools

Video processing in the browser

Video is the most computationally demanding media to work with, and until recently editing it in a browser was not realistic. WebAssembly changed that: these tools run real encoding and decoding pipelines locally, so trimming, converting, and compressing all happen on your own hardware. The trade-off is honest — processing speed depends on your device, and a long high-resolution file will take longer on a phone than on a desktop. What you gain is that your footage is never uploaded and there is no queue or file-size tier.

What actually determines video file size

Bitrate, not resolution, is the primary driver of file size. Bitrate is how many bits per second the encoder spends, and halving it roughly halves the file. Resolution, frame rate, and codec all influence how much bitrate you need for a given quality: H.264 is the compatibility default, while H.265 and VP9 achieve similar quality at roughly 30 to 50% lower bitrate at the cost of slower encoding and narrower support. If a video is too large, reducing resolution and bitrate together produces a better-looking result than cutting either one alone.

Trimming, converting, and extracting audio

Trimming to remove unwanted footage before any other step is almost always worth doing first, since every subsequent operation then has less data to process. Format conversion is often about compatibility rather than size — MKV is an excellent container that many devices and platforms will not play, and remuxing to MP4 solves that without re-encoding the video. Extracting audio to MP3 discards the video stream entirely, which is the right tool when you only ever wanted the sound from a recording, lecture, or interview.

Choosing settings for a destination

Match your export to where the video is going. Social platforms re-encode everything you upload, so sending a file already near their target specification means their compression has less to strip and the result looks better. Vertical formats at 1080×1920 suit Stories, Reels, and Shorts; 1920×1080 landscape suits YouTube and most embeds. Frame rate should match the source — converting 30fps footage to 60fps adds file size without adding smoothness, since the extra frames are duplicates.