Free Video Converter In your browser, nothing uploaded
This is the general converter. Put in an MP4, MOV, M4V, MKV, TS, 3GP, AVI, WMV, MTS, WebM or MPEG file and get back an MP4 that plays almost anywhere, or an MP3 if you only want the sound. The box above says Video until a file lands, then it names whatever you actually dropped. Every step runs inside this tab through a WebAssembly build of FFmpeg, so the video is never sent to us.
- MP4 or MP3 out
- Nothing uploaded
- Up to 20 files
Convert Video / Auto to MP4
MP4, MOV, M4V, MKV, AVI, WMV, WebM, TS, MTS and more
Up to 20 clips at once
Privacy-first. No uploads. If this helps, share it.
- The file stays on your machine
There is no upload step and no processing queue on someone else's server. FFmpeg runs as WebAssembly in this page, reads the file straight from your disk and writes the result back to your downloads folder.
- It reads what you actually have
The label above stays on Video until a file arrives, then it names the format that turned up. Nothing has to match a page title first, and that holds on the per format pages too, so an MKV dropped on the MOV page is converted rather than refused.
- 20 files per batch, 1 GB each
Queue a folder of camera clips or old recordings in one go. The build is single threaded, so the queue moves through one file at a time, and each finished result can be saved on its own or with the rest as a zip.
How to convert a video online
Add the file, pick MP4 or MP3, download the result. When the streams inside already fit an MP4, they are copied across untouched, which is quick and loses nothing. When they do not, the video is re-encoded to H.264 with AAC audio, the combination phones, browsers, editors and upload forms are most likely to accept. MP3 comes out at 128 kbps and 44.1 kHz. There is no account and no upload, so the file only moves when you choose to send the result somewhere.
- Add your video
- Choose MP4 or MP3
- Download the result
MP4 or MP3: what each one gives you
Both outputs come from the same file and the same page, so the only real question is whether you still need the picture. Keep the picture and you want MP4. Only need the words or the music and MP3 is a fraction of the size. Here is how the two compare on the things that usually decide it.
| What you get | MP4 output | MP3 output |
|---|---|---|
| What is inside | Picture and sound, kept together in one file | Sound only. The picture is dropped and cannot be recovered from the MP3 |
| How it is written | Copied as-is when the streams fit MP4, otherwise H.264 with AAC | 128 kbps at 44.1 kHz, the usual setting for speech and general listening |
| How long it takes | Close to instant when the file only needs remuxing, roughly the length of the video when it needs a full re-encode | Quick even on long files, because only the audio track is decoded and written |
| Where it plays | Phones, browsers, TVs, editors, chat apps and upload forms | Music players, podcast apps, car stereos, voice recorders and transcription tools |
| Size on disk | About the same as the source when it is remuxed. A re-encode can land higher or lower, depending on how the original was made | Small and predictable, roughly a megabyte per minute at 128 kbps |
You can switch between the two with the To dropdown on the converter above without leaving this page. If you want the detail for one specific input format, the dedicated pages cover the quirks of each one.
The two ways a file becomes an MP4
Converting is worth doing when a file opens on the machine it came from and nowhere else, and MP4 is the format that stops that happening. Getting there takes one of two routes. MP4 is a container, a box that holds a video track and an audio track. If the tracks in your file are already the kind MP4 accepts, they can be lifted out and dropped into a new box untouched. That is a remux, it is near instant, and the picture that comes out is bit for bit what went in. MP4, MOV, M4V, MKV, TS and 3GP files usually qualify, because they tend to carry H.264 already. AVI, WMV, MTS, WebM and MPEG files do not, so their video has to be decoded and written again as H.264. That is a re-encode, and it is the slow path.
The honest tradeoff: a re-encode is generational, so the new file is built from the decoded picture rather than the original data, and it never comes back sharper than what went in. It also runs at roughly real time in a single threaded browser build. A forty minute AVI takes something close to forty minutes with the tab open. A forty minute MOV that only needs remuxing is done in seconds.
Where the MP4 actually plays, and what still will not
H.264 with AAC in an MP4 container is the closest thing video has to a universal format. Hardware decoders for it sit in phones, laptops, smart TVs, consoles and set top boxes going back well over a decade, which is why upload forms and social platforms ask for it by name. That is what this converter writes whenever a file has to be re-encoded. Where the source already holds streams an MP4 can carry, they are copied instead, which keeps the quality exactly as it was. Newer codecs such as H.265 play in most current browsers and devices but not in as many places as H.264, so a copied file travels slightly less widely than a re-encoded one.
It plays: iPhone and Android, Safari, Chrome, Firefox and Edge, the built in players on Windows and macOS, QuickTime, VLC, smart TVs, Premiere, DaVinci Resolve, iMovie, CapCut, and upload forms that ask for MP4.
It will not fix a file you are not allowed to open. DRM protected video, including films and shows bought from iTunes that arrive as M4V, cannot be decoded by any converter, and those files fail here rather than converting badly.
It does not change the picture itself. The frame size, the aspect ratio, the length and the framing come through as they were, because this tool converts formats and does not edit video.
Convert a video in three steps
All three happen in this tab.
Add your files
Drag them onto the box above or browse your device. MP4, MOV, M4V, MKV, TS, 3GP, AVI, WMV, MTS, WebM and MPEG are all read, up to 20 files at a time and 1 GB each.
Pick the output
MP4 is selected already. Switch the To dropdown to MP3 if you only want the sound. The tool works out on its own whether the MP4 can be remuxed or needs a re-encode, so there is nothing else to set.
Download and use it
Save each result on its own or take the batch as a zip. Files that were remuxed appear almost immediately, and files that needed re-encoding show progress while they work.
Why use this converter rather than an upload site
Most free converters are a web form in front of a server farm. Your file goes up, waits in a queue, gets converted by someone else's CPU and comes back. That model has consequences worth naming.
The fast path stays fast
Many upload based converters re-encode everything, because it is simpler to run one pipeline than to inspect each file. A MOV that could have been remuxed in seconds comes back softer than it went in. Here the tracks are checked first, and the video is only re-encoded when they genuinely will not fit in an MP4.
No queue, no daily quota, no watermark
There is nothing to wait behind, because the only machine involved is yours. There is no daily conversion count, no size tier to buy, no email address for a download link and no logo burned into the corner of the result.
One door, or the specific room
This page takes whatever you have. When you want the detail for one format, the dedicated pages go deeper: what a MOV actually contains, why WebM always needs re-encoding, what to expect from an AVI recorded in 2006. Same converter underneath, more context around it.
It does one job and says so
This converts between formats and can pull the audio out. It does not crop, trim, resize, rotate, add subtitles or strip DRM, and it will not pretend otherwise halfway through a two hour encode. Knowing what a tool refuses to do saves more time than any feature list.
Converting is a strange thing to hand a stranger
The videos people convert are rarely public ones. They are interview recordings, footage for a legal matter, a scan from a clinic, unreleased client work, a camera card from a wedding, a clip from a doorbell. Uploading all of that to an unnamed server to change the letters after the dot is a large trade for a small job.
Nothing here is uploaded, so there is no retention policy to read and no copy of the file sitting on a machine you cannot see. We never learn the file name, the length or that a conversion happened at all. Close the tab and the only copy of the result is the one on your disk.
What that means in practice
- The video is read from your disk and written back to it
- No account, no email, no download link to wait for
- No watermark and no size tier to unlock
- Your own processor does the work, so a re-encode takes real time
Video conversion troubleshooting
Related conversions
Need a different format? These open the same private browser converter, preconfigured for another conversion.
- AVI to MP4
Turn old DivX and XviD AVI files into MP4 that phones will actually play. Runs in your browser.
Open this converter - WMV to MP4
Turn old Windows Media files into MP4 that modern devices will actually open.
Open this converter - M4V to MP4
Turn Apple's M4V into a standard MP4. Seconds, no quality loss, no upload.
Open this converter
More free tools
Frequently asked questions
Add the file to the box at the top of this page, choose MP4 or MP3, and download the result. There is no account, no upload and no watermark, and nothing is held back behind a paid tier.
Last reviewed on 15 August 2026 for browser-based video conversion.