WEBM to MP4 Converter

Turn a web-only WEBM into an MP4 that uploads to TikTok and Instagram and plays on any phone. Free, in your browser, no signup.

Select WEBM file →

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Choose Files

Click or drag and drop to upload files

We support most file types including: MP4, MOV, WEBM, AVI, MP3, WAV, PNG, JPEG, GIF, MKV, PDF, FLAC, TIFF!

EchoWave is used by creators, marketers, educators, and businesses to convert and edit media online.

Updated June 2026

WEBM is built for browsers, which is exactly why it gives you trouble everywhere else: TikTok and Instagram reject it, iPhones will not open it, and most editors skip it. MP4 fixes all of that. EchoWave rewraps your WEBM into an MP4 with H.264 video and AAC audio, the combination phones, social apps, and editing software expect, all free and in your browser with no signup.

Free, no sign-upNo account, no trial

Runs in your browserNothing to install

Works on every devicePhone, tablet, laptop

No watermarkClean output, every time

How it works

How to convert WebM to MP4

1
Upload your WebM
Drag your WebM onto the converter or pick it from your device. Nothing to install.
2
Choose MP4 and convert
Select MP4 as the output and start. Free, with no sign-up and no watermark.
3
Download your MP4
Save the finished MP4, or open it in the editor to trim, crop, or resize it first.

Try it

Estimate your MP4

Pick a video bitrate and a length to see the MP4 file size before you convert.

Video bitrate

Length5 min

1 min30 min

Estimated MP4 size183MBSharp 1080p

An estimate. Real size varies with resolution, frame rate, and how much the picture moves.

The formats

WebM vs MP4

WebM

Open video built for the web

Type: Open web video container
Holds: VP8 or VP9 video with Vorbis or Opus audio
Typical size: Small at good quality
Plays on: Chrome, Firefox, Edge, and Android

Best for:Video embedded on web pages

MP4

MPEG-4 Part 14

The video format that plays everywhere

Type: Video container
Holds: H.264 video plus AAC audio, sometimes subtitles
Typical size: Large, it carries video
Plays on: Phones, browsers, TVs, almost any player

Best for:Watching and sharing video

Will it lose quality?

When the codecs already match MP4, the converter can change the container without re-encoding, so the picture stays identical.
When the video has to be re-encoded for MP4, a high bitrate keeps it visually close to the WebM.
Converting cannot add detail the WebM never had. The output is at best as good as the source.

Use cases

What people use it for

Play anywhereMake a clip your device supports

Video editorsGet footage your software accepts

Web videoUse a format browsers play

CourseworkHand in a standard video file

SharingSend a clip people can open

Troubleshooting

If something looks off

The MP4 will not play

Some players are picky about codecs. Try it in VLC, which opens almost anything, or convert again and let the converter re-encode the video.

The file got larger

A format change can shift the size, and re-encoding at a high bitrate adds overhead. Lower the bitrate or trim the clip for a smaller file.

Audio and video drift out of sync

Re-download the source and convert again. If a long recording drifts, splitting it into shorter pieces usually fixes the sync.

FAQ

WebM to MP4 questions

Why does my WEBM not upload to TikTok or Instagram?

TikTok and Instagram are built around MP4 and do not accept WEBM, even though YouTube and Facebook do. Converting your WEBM to MP4 gives you a file those mobile apps will take, so you can post a clip that was recorded or downloaded for the web.

How do I convert WEBM to MP4?

Upload your WEBM, choose MP4 as the output, and start the conversion. When it finishes, download the MP4 or open it in the editor to trim, crop, or add captions first. No account and no software install are needed.

Why will my WEBM not play on iPhone or in QuickTime?

Apple devices and QuickTime do not support the VP8 and VP9 video inside most WEBM files, so the clip refuses to open. Converting to MP4 re-encodes it to H.264, which iPhone, iPad, Mac, and QuickTime all play natively.

Will converting WEBM to MP4 reduce the quality?

WEBM and MP4 use different video codecs, so the picture is re-encoded rather than just rewrapped. At a high bitrate the MP4 stays visually close to the source, and converting can never add detail the WEBM never had, so the output is at best as good as the original.

Is the WEBM to MP4 file bigger or smaller?

The two formats compress similarly, so the MP4 is usually close in size to the WEBM rather than dramatically larger or smaller. If you need a smaller file, lower the bitrate in the estimator above or trim the clip before converting.

Does the WEBM to MP4 converter work on Mac, Windows, iPhone, and Android?

Yes. It runs in any browser, so you can convert WEBM to MP4 on macOS, Windows, Chromebook, Linux, iPhone, iPad, and Android with nothing to install and no account to create.

Is the WEBM to MP4 converter free?

Yes. EchoWave converts WEBM to MP4 with no signup, no file-count limit, no trial, and no watermark on the output. Upload your video, convert it, and download the MP4 from your browser.

Will the sound come across in the MP4?

Yes. The Vorbis or Opus audio in your WEBM is re-encoded to AAC inside the MP4, which keeps the sound and matches what phones and editors expect. If a clip ever plays silent, re-download the source WEBM and convert it again.

Can I edit the video after converting it to MP4?

Yes. Once you have the MP4 you can open it in the editor to trim, crop, resize, or add subtitles before you upload or share it.