Video
Convert HEVC to H.264 on Mac So Any PC Can Play It
To make an HEVC (H.265) video play on any PC, re-encode it as H.264 in an MP4. On a Mac you can do that with Apple’s built-in avconvert command, with ffmpeg, or with Smol’s Convert. Expect the H.264 file to be larger than the HEVC original.
Why does my iPhone video not play on Windows?
iPhones record in HEVC by default. Apple calls the setting High Efficiency, and says it uses less storage than H.264 at the same visual quality, per its page on HEIF and HEVC media on Apple devices. Windows PCs, older TVs and some web tools cannot play HEVC without a codec add-on, so the file shows a black screen, audio only, or an error.
H.264 plays almost everywhere. Converting trades disk space for compatibility. For the codec comparison itself, read H.265 vs H.264.
Can I stop my iPhone recording HEVC in the first place?
Yes. On the iPhone, open Settings, tap Camera, then Formats, and choose Most Compatible. New photos and videos are then saved as JPEG and H.264. Apple also notes that sharing through AirDrop, Messages or email to a device that does not support the newer formats may convert the media automatically. Videos you already shot stay HEVC, so you still need to convert those.
How do I convert HEVC to H.264 on a Mac for free?
macOS ships with a converter called avconvert. Its non-HEVC presets write H.264:
avconvert --source clip.mov --preset Preset1920x1080 --output clip-h264.mp4We ran Preset1280x720 and PresetHighestQuality on a HEVC test clip and ffprobe showed H.264 video and AAC audio both times. The presets scale down to their size but did not upscale our 640-wide clip. Run avconvert --help for the full preset list. There is no quality slider, only presets, and the outputs on our clip were large (about 450 KB for a 74 KB original).
For exact control, ffmpeg (brew install ffmpeg) lets you set a bitrate:
ffmpeg -i clip.mov -c:v h264_videotoolbox -b:v 8M -c:a copy clip-h264.mp4Pick a bitrate near the source’s, then raise it if the picture looks soft. Options are on the ffmpeg H.264 guide.
How do I convert HEVC to H.264 with Smol?
Drop the videos into Smol, choose Convert, set MP4 as the output and H.264 as the codec (our test used that setting through Smol’s MCP interface), then run it. On our 74,092-byte HEVC test clip that wrote an H.264 MP4 of 135,386 bytes, about 83% bigger. That is normal and expected: H.264 needs more bits for the same picture.
One trap. When we ran Compress with the H.264 codec on the same clip, Smol kept the original HEVC file and reported it as already optimized, because the H.264 result would have been larger. If you need H.264 for compatibility, use Convert, not Compress, and check the output codec in QuickTime Player’s Movie Inspector (Window > Show Movie Inspector).
How big is the H.264 file compared with the HEVC original?
| Method (5 s, 640 x 360 test clip) | Output codec | Bytes |
|---|---|---|
| HEVC original | HEVC | 74,092 |
| avconvert Preset1280x720 | H.264 | 456,743 |
| avconvert PresetHighestQuality | H.264 | 451,652 |
| ffmpeg, h264_videotoolbox, 2 Mbps | H.264 | 564,727 |
| Smol Convert, H.264 | H.264 | 135,386 |
| Smol Compress, H.264 | HEVC (original kept) | 74,092 |
The clip is a synthetic test pattern, so the sizes show the direction, not what your footage will do. The spread between tools comes mostly from how many bits each one spends by default.
When is Smol the wrong tool for this?
For one clip, use avconvert. It is built in and needs nothing installed. If you only need to send a video to a Windows user, switching the iPhone to Most Compatible or letting AirDrop and Mail convert it can be enough. Both are free.
Smol earns its $29 when you have a folder of iPhone clips to convert in one go, mixed with photos and PDFs, and want a smaller file as well, from a Finder right-click and with nothing uploaded. Pricing is on the buy page. If size is the real problem, see the best video compressor for Mac.
More conversions: MOV to MP4, MKV to MP4 and the best file converters for Mac.
How we checked this
Made a 5-second HEVC/AAC test clip with ffmpeg 8.1.1 on macOS 27.0.1; converted it with avconvert, ffmpeg and Smol 1.0.35 (via its MCP interface) and checked codecs and sizes with ffprobe. Windows playback was not tested. Facts last checked . We make Smol, so treat our claims about it with the same care as any vendor’s, and see our editorial policy.
HEVC to H.264: common questions
Is HEVC the same as H.265?
Yes. HEVC (High Efficiency Video Coding) is the standard name for H.265. H.264 is the older codec it replaced. HEVC files are smaller at the same quality, but fewer older devices and apps can play them.
How do I convert HEVC to MP4 on Mac?
An MP4 can hold either codec. If you only need a different container, a stream copy keeps HEVC inside an MP4. If the goal is playback on a PC, re-encode to H.264 as shown above, using avconvert, ffmpeg or Smol Convert with H.264 selected.
Does converting HEVC to H.264 reduce quality?
It re-encodes the video, so some loss is possible, but at a high enough bitrate it is hard to see. The bigger change is file size: H.264 needs more bits for similar quality, so the output grew in all our tests.
Why is my H.264 file bigger than the HEVC original?
H.264 is less efficient than HEVC, so the same picture takes more data. In our test the HEVC clip was 74,092 bytes and the H.264 versions ranged from 135,386 to 564,727 bytes depending on the tool and its default bitrate.
Is there a way to avoid converting every iPhone video?
Yes. Set Settings > Camera > Formats > Most Compatible on the iPhone so new videos are recorded as H.264. Existing HEVC videos stay as they are, and Apple notes that sharing to a device without support may convert them automatically.
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