VidSlim

Compress Video Online — Private, Free, No Upload

Shrink any video to an exact file size, entirely in your browser. Powered by FFmpeg WebAssembly — your file never leaves your device. No watermark, no sign-up, no file-size tricks.

Drag & drop a video here, or

Processed 100% in your browser — your file never leaves your device.

MB

Compress for a specific platform

Compress to an exact size

Compress by type & quality

Why in-browser compression is different

Most online video compressors upload your file to a server, process it there, and make you download the result. That means waiting through two large transfers and trusting a third party with your footage. This tool runs FFmpeg — the same engine professionals use — compiled to WebAssembly inside your browser. Nothing is uploaded, there is no queue, and confidential videos stay on your machine.

How exact-size compression works

Enter a target size and the tool computes the precise video bitrate from your clip's duration: total bit budget = size ÷ length, minus a fixed audio allocation and container overhead. The encoder then targets that bitrate, typically landing within a few percent of the size you asked for — no trial and error.