MP4 to H.264 Converter
Re-encode the video inside an MP4 to H.264 (AVC), the codec that upload forms, smart TVs, projectors and video editors name when they say they support MP4.
Video Converter
or drop MP4, MOV, MKV … files here ·
Max 95 MB per file· Up to 20 files· Deleted after 30 minutes
Files are processed on our servers and deleted after 30 minutes.
Lower is better quality and a bigger file. 18 looks identical to the source, 23 is the default, 28 and above shows visible softening.
Frames per second. Keep the source rate unless a platform asks for a specific one; 15–20 fps is plenty for GIFs.
Only used for PowerPoint files and single still images: how long each slide or picture stays on screen.
Auto uses AAC for MP4/MOV and Opus for WebM. Copy keeps the original sound untouched when the new format supports it.
192 kbps is transparent for music; 128 kbps is enough for speech.
Width of the animation in pixels; height follows the aspect ratio. 480 px suits chats, 720 px or more gives a high-quality GIF but a much larger file.
GIF holds at most 256 colors. Fewer colors make a smaller file but cause banding on gradients and skin tones.
Mixes palette colors in a fine pattern to hide banding. Sierra gives the smoothest result; none gives the smallest file.
Whether the animation repeats endlessly or plays one time and stops.
Optional. Seconds (e.g. 75) or minutes:seconds (1:15). Leave empty to start at the beginning.
Optional. Same format as the start time. Leave empty to keep everything up to the end.
The converted file will be at or just under this size.
How to use this tool
- 1
Upload the MP4 files
Add up to 20 MP4 files, 95 MB or less each, from a phone, a drone, a screen recorder or a download.
- 2
Check the codec settings
Video codec is pinned to H.264 and Quality (CRF) to 20, a little above the default for a copy you may edit. Audio codec AAC makes the sound match.
- 3
Convert and replace
Press Convert to MP4, then upload or import the new file where the old one was refused. Our copies are deleted after 30 minutes.
How do I convert an MP4 to H.264?
Upload the MP4, keep Video codec on H.264 and press Convert to MP4. The picture is re-encoded to H.264 (AVC) and the sound to AAC, and the file keeps the .mp4 extension.
MP4 is the box, H.264 is what plays
- H.264AVC · MPEG-4 Part 10 · x264 output
- A video compression standard approved in 2003 by the ITU-T and ISO/IEC through their Joint Video Team. It is published both as ITU-T H.264 and as MPEG-4 Part 10, and nearly every phone, TV, browser and graphics chip of the past fifteen years decodes it in hardware.
"Supports MP4" on a spec sheet almost always means H.264 video with AAC sound inside an MP4. When the same container holds H.265 from an iPhone or drone, AV1 from a game capture, or MPEG-4 Part 2 from a 2008 camera, the device sees a familiar extension and still shows an error, a black frame or sound only.
Converting to H.264 is the fix that works across all of those cases. For iPhone and GoPro footage specifically, the HEVC to MP4 converter explains the H.265 side in more depth.
MP4 to H.264: input and output
MP4
MPEG-4 video
MP4 (MPEG-4 Part 14) is a multimedia container standardised by ISO/MPEG and based on Apple's QuickTime format. It usually holds H.264 or HEVC video with AAC audio, and can also carry subtitles, chapters and metadata. It is the most compatible video format in the world, playing on phones, browsers, TVs, game consoles and social platforms. The video inside is almost always lossy, so repeated re-encoding gradually reduces quality.
- Compression
- Lossy
- Transparency
- –
- Animation
- –
- Introduced
- 2001 · Moving Picture Experts Group (MPEG)
H264
H.264 / AVC video
H.264, also known as AVC, is a video codec standardised by ITU-T and ISO/MPEG in 2003. It is the most widely supported codec in the world and is used in most MP4 files, Blu-ray discs, video calls and web video. A .h264 file is a raw video stream with no container or audio track, so many players need it wrapped in MP4 first. It needs more bitrate than HEVC or AV1 for the same quality.
- Compression
- Lossy
- Transparency
- –
- Animation
- –
- Introduced
- 2003 · ITU-T VCEG and ISO/IEC MPEG
People re-encode an MP4 to H.264 when the extension is right but the codec is not: a form, TV or editor that promises MP4 support quietly means H.264, and the file holds HEVC, AV1 or something older.
How much quality an H.264 copy keeps
- CRF 16
Near lossless; files can outgrow the source
- CRF 20
Preset here; safe for editing and re-export
- CRF 23
Default; fine for watching and sharing
- CRF 28
Visible softening; small files for chat
H.264 profiles and levels: why a player can still refuse the file
H.264 comes in profiles, sets of features a decoder must support. Baseline drops B-frames and was used by early iPods and video calls; Main and High add tools that save space and are what modern players expect. Levels cap the frame size and rate a decoder must handle: Level 4.0 covers 1080p at 30 fps, while 4K at 60 fps needs Level 5.2.
So if an older TV or projector rejects even the H.264 copy, the level is the likely reason. Choose 1080p or 720p under Resolution and 30 fps under Frame rate, and the file falls into the range most hardware accepts. To shrink the result for a message instead, see how to compress video for Discord and email.
MP4 to H.264 questions
Is H.264 the same thing as MP4?
No. MP4 is the container that holds the streams, and H.264 is one of several video codecs that can sit inside it. Most MP4 files use H.264, which is why the two get mixed up, but phones and cameras increasingly write H.265 or AV1 into the same .mp4 name.
Which MP4 files actually need converting to H.264?
Files with H.265 (HEVC), AV1 or VP9 video when the target is older hardware or a strict upload form, and very old MP4s with MPEG-4 Part 2 video from early phones and cameras. If the file is already H.264 and plays, leave it alone.
What happens if my MP4 is already H.264?
It is decoded and encoded again, which costs a little quality at CRF 20 and fixes nothing about the codec. Re-encode an H.264 file only to change something else, such as a variable frame rate, the resolution, or a broken index; the MP4 to MP4 converter covers those repairs.
Does the H.264 copy keep 4K and 60 fps?
Yes, with Resolution and Frame rate on Same as source. Note that 4K at 60 fps needs H.264 Level 5.2, which some TVs and older laptops cannot decode; choose 1080p for those.
Which H.264 settings do YouTube and X recommend?
YouTube's upload guidelines ask for H.264 with progressive scan and the High Profile, plus AAC-LC sound in an MP4 container. X's media guidelines also list H.264 High Profile with AAC. An MP4 from this page matches the codec part of both.
Is H.264 royalty-free?
No, its patents are licensed through a pool, today run by Via LA. Watching and sharing personal videos is not affected, and Cisco's free OpenH264 build is why browsers such as Firefox can play and send H.264 in video calls.