Convert · runs on your device

Convert HEVC to MP4 in your browser

HEVC is a codec, not a container, and MP4 can already hold it — so "HEVC to MP4" means one of two different jobs, and this page lets you choose the right one explicitly.

Nothing is uploaded

Drop video files here

MP4 · MOV · MKV · M4V · TS

Choose video files to convert

Output format

Plays on effectively every browser, phone, TV and editor when it holds H.264 and AAC.

Video codec

The universal baseline. Hardware decoding exists on essentially every device sold since 2010.

How to size the output

A constant quality target. File sizes vary with how demanding the footage is.

Quality — 8 of 10

Resolution limit

Files smaller than the limit are left alone. Capping usually looks better than lowering the bitrate.

Frame rate

Audio

Fast rewrapCopy streams without re-encoding when the codecs already fit

Lossless and near-instant when it applies. It cannot reduce file size, so turn it off if you need a smaller file.

This conversion is the one people most often get wrong, through no fault of their own. HEVC (also called H.265) is a video codec. MP4 is a container that carries codecs. An HEVC video is very often already inside an MP4 file, which means the request usually is not really about the container at all.

There are two genuinely different jobs hiding behind the phrase. If your HEVC video sits in a MOV or MKV file and you need it in MP4, that is a rewrap: seconds, no quality loss, same file size. If your video will not play on the device you need it on, the container is irrelevant — the problem is that the device cannot decode HEVC, and the fix is re-encoding to H.264, which is slower and costs some quality.

Video Mender asks which of those you want rather than guessing. "Rewrap to MP4, keep HEVC" copies the streams across. "Re-encode to H.264" produces a file that plays essentially everywhere, at the cost of a larger file for the same quality, because H.264 is the less efficient codec.

What this actually does to your file

Rewrap or re-encode

MP4 legally carries HEVC, so the fast rewrap path is available whenever you keep the codec. It disappears the moment you ask for H.264, because changing codec means decoding and encoding every frame.

Quality

Rewrapping is lossless. Re-encoding HEVC to H.264 is lossy and the file usually grows by 30–60% at matched quality, because H.264 needs more bits to say the same thing.

Rewrapping HEVC into MP4 does not make it play on a device that cannot decode HEVC. If playback is the problem, choose H.264.
Re-encoding to H.264 makes the file larger at the same quality. That is the codec difference, not a bug.
Some HEVC files use 10-bit colour. Re-encoding to 8-bit H.264 can introduce mild banding in gradients.

How to use this page

Add the files holding HEVC video — they may be .mp4, .mov, .mkv or .ts.
Decide what you actually need: keep HEVC for a fast lossless rewrap, or choose H.264 for maximum playability.
If you chose H.264, pick a quality preset; High is the default.
Start the queue and download the results.

Where the result plays

Checked against the containers and codecs this page produces, stated conservatively.

Target	Works	Detail
iPhone and Mac (2018+)	Yes	Decodes HEVC in hardware. Rewrapping is enough; re-encoding is unnecessary.
Older phones and PCs	Partly	HEVC decode is hit and miss before roughly 2016 hardware. Re-encode to H.264 for these.
Chrome and Firefox	Partly	HEVC playback in browsers depends on the OS and on licensing. H.264 always works.
Older editors and TVs	No	Many refuse HEVC entirely. H.264 MP4 is the safe choice.

The formats involved

Format	Read	Write	What it is
MP4	Yes	Yes	The MPEG-4 Part 14 container. It is a wrapper, not a codec — an MP4 usually holds H.264 or HEVC video with AAC audio.
MOV	Yes	Yes	Apple QuickTime. Structurally a close cousin of MP4, which is why MOV files can often be rewrapped to MP4 with no re-encode.
MKV	Yes	Yes	Matroska. The most permissive common container: it will carry almost any codec, plus multiple audio tracks, chapters and subtitles.
M4V	Yes	Yes	Apple's MP4 variant used by iTunes. Byte-for-byte it is an MP4; the extension exists so iTunes can flag optional FairPlay DRM.
TS	Yes	No	MPEG transport stream: a broadcast and HLS format built for streams that can be joined mid-flow, so it has no single global header.

Tested limits

Real ceilings measured on real devices, not a marketing claim of unlimited.

Limit	Desktop	iPhone / iPad	Why
File size — rewrap	1.3 GiB	384 MiB	Rewrapping never decodes a frame, so it tolerates far larger files.
File size — re-encode	1.0 GiB	256 MiB	Decoding holds uncompressed frames in memory, which is the real constraint.
Clip length — re-encode	4:00:00	30:00	Beyond this, progress reporting and memory behaviour stop being dependable.
Resolution — re-encode	4096 × 2160	1920 × 1080	A 4K frame is about 12 MB decoded, before the encoder allocates anything.

If something goes wrong

I rewrapped to MP4 and it still will not play.

Then the container was never the problem: the player cannot decode HEVC. Run the file again with H.264 selected as the video codec.

My H.264 output is much bigger than the HEVC input.

Correct and expected. HEVC is roughly 40% more efficient, so matching its quality in H.264 costs more bits. Lower the preset or set a target size if size matters more than fidelity.

Colours look washed out after re-encoding.

The source is likely 10-bit or HDR. Converting to 8-bit H.264 without tone mapping can shift the look; keep HEVC and rewrap instead if the original appearance matters.

Your video never leaves this device

This is a structural property of the application, not a policy we ask you to take on trust. There is no upload endpoint, no API route and no server action anywhere in the codebase, so there is nowhere for a video to be sent even by mistake.

Conversion runs in WebAssembly inside this browser tab. The engine is served from this domain and loaded only when you start a job.
The Content-Security-Policy restricts network connections to this origin, so the page is not permitted to contact a third party at all.
Nothing is stored. Close the tab and every queued file and finished output is gone — which is also why you should download results before you leave.
There are no accounts and no AI. Anonymous page views are counted — which page, roughly what country, what kind of device — and nothing whatsoever about your files.

The repository contains a test that fails the build if any media byte is passed to fetch, XMLHttpRequest, sendBeacon or a WebSocket. See the privacy page for how that is verified.

Questions

Is HEVC the same as MP4?

No, and this is the core confusion. HEVC is a codec that compresses the picture; MP4 is a container that stores compressed tracks. An MP4 can contain HEVC, H.264 or several other codecs.

Should I rewrap or re-encode?

Rewrap if you need a different container and your devices already play HEVC — it is instant and lossless. Re-encode to H.264 if playback is failing, accepting a bigger file and a small quality cost.

Why does my iPhone record HEVC if it plays so poorly elsewhere?

Because Apple hardware decodes it efficiently and the files are far smaller. The trouble starts when those files leave the Apple ecosystem, which is exactly when this conversion becomes useful.

Does re-encoding HEVC to H.264 lose quality?

Yes, it is a lossy generation. At the High preset the difference is very hard to see, but it exists — no re-encode is free.

Can Video Mender produce HEVC output?

Yes, the pinned build includes an HEVC encoder. It is much slower than H.264 in WebAssembly, so it is offered rather than recommended for batch work.