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Free Video Converter Tools

Convert and compress video right in your browser — MP4, MOV, AVI, MKV, WebM — powered by FFmpeg compiled to WebAssembly. Nothing is uploaded.

MP4 → MP3Video → Compressed VideoMOV → MP4AVI → MP4MKV → MP4WebM → MP4

Convert and compress video in your browser

Convert MP4, MOV, AVI, MKV, and WebM, or shrink a large clip down for email, messaging, or an upload limit — all without sending your footage to a server. The tools run FFmpeg compiled to WebAssembly, the same engine desktop apps use, right inside the page.

Fix videos that won't play

A .mov from an iPhone or a .mkv from a download often won't open in the app you need. MOV to MP4, MKV to MP4, AVI to MP4, and WebM to MP4 repackage the video into MP4 — the format that plays virtually everywhere, from social platforms to presentation software.

Extract audio and compress

Pull the soundtrack out of a video with MP4 to MP3 for a podcast clip or a music track, or use Compress Video to cut file size when a clip is too big to share. You choose the trade-off between size and quality.

Shrink a video for email, WhatsApp, or an upload limit

Most sharing limits are the reason people compress video at all: Gmail attachments stop at 25 MB, Discord's free tier at 10 MB, and plenty of job portals and school upload forms cap out lower still. Compress Video re-encodes your clip with H.264 at a more efficient bitrate, which is where nearly all the savings come from — a phone video shot at a high bitrate often drops by more than half with no visible difference. If it's still too big, trimming the clip or stepping the resolution down from 4K to 1080p cuts far more than squeezing quality further.

Which video format should you convert to?

MP4 with H.264 video and AAC audio is the safe answer for almost everything — it plays on virtually every phone, browser, TV, editor, and social platform, and it's what the other tools here convert into by default. Choose WebM only when you're publishing to the web and control the player, since VP9 gives smaller files but many apps and editors still reject it. MOV, MKV, and AVI are containers worth converting away from rather than to: they're what your camera or a download hands you, not what your destination wants.

Private, no-upload video conversion

Uploading video is slow and, for personal or unreleased footage, risky. Because conversion happens on your own machine, there's no upload wait and nothing leaves your device. Note the FFmpeg engine (~30 MB) downloads once on first use and is then cached, so later conversions start quickly.

Not sure which tool you need?

Video format comparison

FormatTypical codecsBest forWatch out for
MP4H.264 video, AAC audioThe universal choice — phones, browsers, social platforms, editors, TVsVery little; H.265/HEVC inside an MP4 is less widely supported than H.264
MOVH.264, HEVC, or ProResApple cameras and editing — what an iPhone records and Final Cut prefersWindows and Android apps often won't open it; ProRes files are enormous
MKVAlmost anything (open container)Archiving films with multiple audio tracks and subtitles in one fileBarely supported outside dedicated players — social platforms reject it
AVIOlder codecs (DivX, Xvid, MJPEG)Legacy footage from camcorders and old archivesDated and inefficient — much larger files than MP4 at the same quality
WebMVP8/VP9 video, Opus audioPublishing on the web — smaller than MP4 at similar qualityMany editors, phones, and upload forms still won't accept it
Privacy, proven — live
Online
0 BUploaded to our servers
0Requests carrying your data
0Files stored by us
—Processed on your devicedrop a file
Conversions run entirely in your browser. Turn off your Wi-Fi and try it — it still works. Nothing leaves this device.

Frequently asked questions

No. Video conversion and compression run in your browser with FFmpeg WebAssembly, so your footage never leaves your device.

The FFmpeg engine (~30 MB) downloads once on first use, then is cached — subsequent conversions start much faster.

Yes. All in-browser video tools are free with no sign-up and no daily limit.

Yes. MP4 to MP3 extracts the audio track and saves it as an MP3.

Small and medium clips convert smoothly. Very large files depend on your device's memory, since everything runs locally — on low-end phones, expect longer processing.

Run it through Compress Video, which re-encodes with H.264 at a more efficient bitrate — that alone often halves a phone recording. If it still exceeds the limit (25 MB on Gmail), trim the clip or convert a 4K video down to 1080p, which saves far more than compressing harder.

Some, but usually less than you'd expect. Phone and camera footage is recorded at a generous bitrate, so a lot of the file size can go before the picture visibly changes. Heavy compression on already-small or fast-moving clips is where softness and blockiness start to show.

They're containers, not codecs — each wraps video and audio streams differently. MP4 is the universal one that plays almost everywhere, MOV is Apple's format for iPhone recording and Final Cut editing, and MKV holds multiple audio and subtitle tracks but is poorly supported outside dedicated players. Converting between them usually means moving into MP4.

Yes, once the page and engine have loaded, in-browser conversion keeps working without a connection.

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