Add files from where they live
Drop a WEBM file on the box, browse for it, or import it from Dropbox, Google Drive or a link. You can add more files later, and each file gets its own result.
Free WEBM to MP4 converter
Convert WEBM to MP4 online. Add a file, confirm MP4 and download it. A single file needs no account.
Converting WebM to MP4 gives you a video that opens almost everywhere, including iPhones, older Safari versions, televisions and most editing software. The one thing to know is that this is a full re-encode: the VP8, VP9 or AV1 picture is rebuilt as H.264, so it takes longer than a simple rewrap and costs a small amount of quality.
Transfers use HTTPS, and files converted on the free tier are deleted within 24 hours, so the result is not a long-term archive. Quality depends on the source file, so open the MP4 file once before you share it.
FromWebMLossy
WebM (web media container based on Matroska)
An open, royalty-free video container built for the web and based on Matroska. It carries VP8, VP9 or AV1 video with Vorbis or Opus audio, and it is what browser screen recorders and many web downloads produce.
ToMP4Lossy
MP4 (MPEG-4 Part 14)
The most widely supported video container, standardised as MPEG-4 Part 14. Players, phones, televisions and editors generally expect it to hold H.264 or HEVC video with AAC audio, although the container can technically carry other codecs too.
Why use indox to convert WEBM to MP4?
Watch the job run
A progress bar shows the file moving through the conversion. If you picked the wrong file, cancel and start again.
Download it or hand it on
Save the MP4 file, copy a share link or convert it to another format. Free-tier output expires on its own after 24 hours.
What changes
- The video codec changes from VP8, VP9 or AV1 to one that MP4 players expect, normally H.264, which means every frame is decoded and compressed a second time.
- Audio moves from Vorbis or Opus to AAC, another lossy codec, so the soundtrack is also re-encoded, though the difference is rarely audible at ordinary bitrates.
- Compatibility widens considerably: the result plays in QuickTime, iMovie, Premiere Pro, PowerPoint, smart televisions and messaging apps that often refuse a WebM file outright.
- File size can go either way, because VP9 and AV1 compress more efficiently than H.264, so an MP4 of similar visual quality is often somewhat larger.
How do I convert WEBM to MP4 online?
- 1
Add your WEBM file
Drop your WEBM file into the converter (or choose a file from disk).
- 2
Pick MP4 and press Convert
Confirm MP4 as the output format and start the conversion.
- 3
Download the MP4 file
Download the MP4 file when it is ready. Start another conversion anytime.
What do I get from indox's WEBM to MP4 converter?
You upload a WEBM file, indox converts it to MP4, and you download the result. A single file needs no account, and nothing is installed.
- No install and no account for a single file
- MP4 output you can download or share
- Progress while the job runs, with a cancel button
- Free-tier files are deleted within 24 hours
What are the limits for WEBM to MP4?
Size
The upload box shows the live size limit before you add a file. Signing in raises it, and paid plans raise it further.
Formats
WEBM in, MP4 out. Pick another output on the converter if you need a different format.
Privacy
Files are encrypted in transit over HTTPS and processed on indox infrastructure.
Deletion
Free-tier files are deleted automatically within 24 hours after the job finishes.
Limits worth knowing
- Quality cannot improve. Re-encoding a lossy video with another lossy codec always loses a little, and heavy compression in the source stays visible.
- Transparency is lost. WebM with VP8 or VP9 can carry an alpha channel, but the H.264 video normally used in MP4 cannot, so clear areas become solid.
- Screen recordings often have a variable frame rate. Depending on the source, that can show up as audio drifting out of sync in some editors.
- Long or high-resolution recordings take noticeably longer than audio or image conversions, because video re-encoding is heavy work.
What do the free and paid plans add?
Free
- All converters
- Daily credit refresh
- Email support
Basic
- Access to all features
- AI Extract & Doc Chat
- Priority conversions
- Email support
Highest priority
Premium
- Everything in Basic
- Highest priority queue
- Larger file limits
- Priority support
Pay-As-You-Go
- No subscription
- Credits never expire
- Opt-in auto-refill
- Access to all features
Which conversions are close to WEBM to MP4?
AVI to MP4
Older video files at a smaller size
MOV to MP4
iPhone and Mac video that plays anywhere
MKV to MP4
Video for phones, TVs and editors
MP4 to MP3
The sound from a video
Related conversionsReverseMP4 to WEBM
Who can use a WEBM to MP4 converter?
When to use it
- Opening a browser screen recording in iMovie, Final Cut Pro or Premiere Pro, which commonly reject WebM on import.
- Sending a clip to someone on an iPhone or an older Mac where WebM playback is unreliable.
- Uploading a video to a social platform, learning system or slide deck that accepts MP4 files only.
- Playing a downloaded web video on a television, games console or car screen from a USB stick.
Where can I read more about converting files?
Do it all with indox
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WEBM to MP4 FAQs
Does converting WebM to MP4 lose quality?
Yes, slightly. Both formats use lossy video codecs, and moving from VP9 or AV1 to H.264 means decoding the picture and compressing it again, which discards a little more detail. On a clean source the difference is usually hard to see. On a recording that was already heavily compressed, blockiness and banding can become more noticeable.
Can I just rename .webm to .mp4?
No. Renaming changes the label, not the contents, so the file is still a WebM container holding VP9 and Opus streams. A forgiving player such as VLC may open it anyway by inspecting the data, but an iPhone, iMovie or a strict uploader will still reject it. The streams have to be re-encoded and written into a real MP4 structure.
Why won't my WebM file play on iPhone or in Safari?
Because Apple was late to support the codecs WebM uses. Older versions of iOS and Safari cannot decode VP8 or VP9 at all, and newer ones support them only partly, with behaviour that varies by version and device. The Photos app, iMovie and QuickTime Player expect H.264 or HEVC in an MP4 or MOV file instead.
Why is the MP4 bigger than the WebM?
Usually because H.264 needs more data than VP9 or AV1 to reach the same visual quality. Those newer codecs are noticeably more efficient, so matching the look of the source produces a larger file. The opposite also happens: a WebM recorded at a generous bitrate can shrink once it is re-encoded.
Why does my WebM screen recording show no duration or refuse to seek?
WebM files written live by a browser recorder often lack a stored duration and a seek index, because the recorder streams data out before it knows how long the clip will be. Players then show a blank timeline or cannot skip ahead. Converting writes a complete MP4 with a proper index, which usually fixes both problems.
Will a transparent WebM stay transparent as MP4?
No. Transparent WebM clips store an alpha channel alongside VP8 or VP9 video, and standard H.264 in MP4 has nowhere to keep it. The transparent regions are filled with a solid colour, typically black. If you need transparency for overlays or animated stickers, keep the WebM, or use a format designed for alpha such as ProRes 4444 in MOV.