Make videos small enough to send
Phone videos are enormous — a minute of 4K footage can top 400 MB, while WhatsApp caps files at 64 MB and email at 25 MB. This tool re-encodes video with the efficient H.264 codec at a quality level you choose, typically shrinking files by 60–90%.
Everything runs in your browser via WebAssembly: your videos never touch a server, so private family clips stay private.
How to compress a video
Drop a video above, pick a quality preset (Balanced is right for most uses), and press Compress. The first use downloads the conversion engine (~31 MB, cached afterwards). Re-encoding is CPU-intensive and runs at roughly real-time speed — a 2-minute clip takes a couple of minutes — so it is best suited to clips rather than feature films.
Unlike most online converters, FileLark never uploads your files to a server. The conversion runs entirely inside your browser using modern web technology, which means it works offline once the page has loaded, there are no file size queues or daily upload limits, and your images can never be stored, scanned, or leaked — they simply never leave your device.
Quality presets explained
Light keeps near-original quality with modest savings. Balanced is visually excellent for phones and social sharing at a fraction of the size. Strong prioritises the smallest file — fine for previews and messaging, visibly softer on large screens. If the result is still too big, also reduce the resolution by trimming your video to just the needed section first.