HEVC to MP4 Converter

Find out why an HEVC or iPhone video will not play, then copy it into MP4 or convert it to H.264 in your browser, without uploading it.

Choose a video

or drop it here

The video is processed on this device and never uploaded.

MP4, MOV, WebM, MKV, AVI, WMV, FLV, 3GP, TS / MTS / M2TS or VOB / MPG

Files over 1 GB can be slow. Very large outputs need a browser that can save straight to a file.

MOV, MP4, M4V and MKV files from iPhones, Android phones and cameras. Raw .hevc / .h265 streams without a container are not supported. The video does not need to play in this browser.

How it works

When you choose a file, the page reads its container and track headers in your browser. It reports the container (MOV, MP4, M4V), the video codec and profile, any HDR signalling, the audio codec, and whether this browser can decode the video, then names the likely problem and one fix.

If the video is already H.264 with AAC or MP3 audio but sits in a MOV or M4V file, the page copies the streams into MP4 without re-encoding. That takes seconds and leaves the quality unchanged.

If the audio is Dolby Digital (AC-3 / E-AC-3), DTS or another format browsers commonly do not play, a plain copy would give a video that plays without sound in Chrome and Firefox. The page then keeps the video as it is and converts only the audio to AAC.

If the video is HEVC (H.265), the page re-encodes it to H.264 with AAC audio at high quality and the original resolution, using the browser's WebCodecs encoder where it can. If this browser cannot decode HEVC, the page says so before you start, and the conversion runs on FFmpeg.wasm, which is much slower.

The video never leaves your device. Everything runs in this browser tab.

Supported files

Inputs: MOV, MP4 and M4V files (iPhone, Android and camera recordings), plus MKV and WebM. HEVC, H.264 and other codecs are diagnosed. Raw .hevc / .h265 elementary streams without a container are not supported.
Outputs: MP4 with H.264 video and AAC audio, MP4 with the original streams copied, or MP4 with the original video copied and the audio converted to AAC.

Limitations

HDR video (PQ / HDR10, HLG, Dolby Vision) is diagnosed and explained but not converted to SDR. A plain conversion to 8-bit H.264 would likely look washed out; copy operations such as the MP4 copy still work.
H.264 is less efficient than HEVC, so a converted file is commonly 1.5 to 2 times the size of the original.
Without WebCodecs HEVC decoding the conversion uses FFmpeg.wasm on one CPU thread. It can take several times longer than the video lasts, and very large files may not fit in its memory.
The copy into MP4 keeps the audio as it is only when it is AAC or MP3. Dolby Digital (AC-3 / E-AC-3), DTS and other audio is converted to AAC (surround sound may be mixed down to stereo where the browser's AAC encoder cannot keep it).
Subtitle and timed-metadata tracks (such as an iPhone's location or camera data track) are not copied into the MP4.

Questions

Why won't my iPhone .mov play on Windows?

iPhones record in HEVC (H.265) by default (Settings > Camera > Formats > High Efficiency). Windows commonly needs the separate HEVC Video Extensions to play it, and many older players and web apps do not support HEVC at all. Converting to H.264 MP4 is the widely compatible fix. If the file turns out to be H.264 already, copying it into MP4 is likely enough.

Is a MOV file with H.264 a problem?

Not necessarily. MOV and MP4 are closely related and many players open both. Some Windows, Android and web players commonly handle MP4 more reliably, which is why the page offers a copy into MP4 without re-encoding rather than a full conversion.

Why does my converted video play without sound?

Commonly because the audio is Dolby Digital (AC-3 or E-AC-3) or DTS, which Chrome and Firefox do not play (Safari usually plays Dolby Digital; browsers commonly play no DTS at all). The page checks for this and, instead of copying that audio, keeps the video as it is and converts only the audio to AAC.

Does converting HEVC to H.264 lose quality?

Any re-encode loses a little detail. The page encodes at high quality and keeps the original resolution, so the loss is commonly hard to see, but the file grows. Copying into MP4 loses nothing, because the streams are not re-encoded.

Why is the converted file larger than the original?

HEVC needs fewer bits than H.264 for the same picture quality. Keeping the quality high while switching to H.264 commonly makes the file 1.5 to 2 times larger. To make it smaller afterwards, lower the quality or resolution in the main converter.

What about HDR videos?

HDR clips look right only in players and on screens that understand their HDR format. Turning them into ordinary SDR video needs tone mapping, which this site does not do yet, so the page explains what it found instead of producing a washed-out file. Exporting or sharing from the iPhone with HDR turned off is usually the most reliable way to get an SDR copy.

Example

A clip recorded on an iPhone with the camera format set to High Efficiency and HDR video turned off is a MOV file. Here it is typically reported as: container MOV (QuickTime), video H.265 (HEVC) with a profile such as “HEVC Main @ L4”, HDR none signalled, audio AAC. The likely issue is the HEVC video, and the fix is the H.264 conversion.

On a browser that can decode HEVC the conversion runs on the WebCodecs encoder; elsewhere the page says it will use FFmpeg.wasm before you start. The result block then shows the engine used, that the video was re-encoded, and the new size next to the original, so you can see the growth for yourself.

The same clip recorded with HDR video on signals HLG instead. The page explains HDR, offers no SDR conversion (only the copy into MP4, which keeps the HDR video as it is), and points to Video Information for the full colour details.