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Convert MOV to WebM Online Free

Your iPhone clip is too heavy for a web page. A MOV to WebM converter is how WebM fixes that.

People convert MOV to WebM for one reason: putting video on a website, usually as a silent looping background or a product clip. Pick where it goes and see how the file size, and the time to first frame on a phone, change.

wallpaperHero backgroundsilent loop, full width

inventory_2Product clipinline, with controls

emoji_emotionsSticker / animated logosmall, transparent

IMG_0871.MOV · 12 s · 4K HEVC · with sound99% smaller as WebM how 186 MB becomes a web file · each step on a log scale

Original MOV4K HEVC · 60 fps

186 MB

Resize4K → 1080p

52 MB

Frame rate60 → 24

22 MB

Remove audiosilent loop

22 MB

VP9 encodehigh compression, it sits behind text

2.6 MB

MP4 backup, same settings3.9 MB · 50% larger than WebM

first frame on 4G< 1 swhole file on 4G1.7 soriginal on 4G124 s

what we change for hero background aspect_ratioResizePhones and laptops never show 4K in a web page.4K → 1080pspeedFrame rate60 fps doubles the size for no visible gain on the web.60 → 24volume_offRemove audioAutoplaying video must be muted anyway, so the track is dead weight.−0.2 MBtuneQuality targetTuned per use: high compression, it sits behind text.VP9 movieConvert to WebM

Open MP4, MKV, MOV, AVI, WMV, FLV, RealMedia, DVD VOB, camcorder MTS or almost anything else, and save it as any of 32 formats. The converting happens in this tab. Your video is never uploaded.

video_fileChoose videos scienceMake a 6 s test clip

memoryThe enginenot loaded

whatFFmpeg compiled to WebAssembly

download≈ 31 MB, once per visit

readsloads with the engine

writes32 targets, checked on load

loads when you convert, or nowdownloadLoad now

~/convert

Your files, then one of 32 targets.

Each file is identified from its first bytes as soon as you add it. Once the engine is loaded it is read in full, so you see the real codecs, size and length before you convert.

filefirst bytessizeinside (read by engine)status

movie close

upload_fileDrop videos hereor click to choose. Any container, any size your device can hold.

Save asreadyno sound trackafter engine loads

Common6 formats

.mp4.avi.mkv.mov.wmv.flv

Web3 formats

.webm.ogv.m4v

Professional5 formats

.mpg.mpeg.vob.mts.m2ts

Mobile2 formats

.3gp.3g2

Legacy4 formats

.rm.rmvb.asf.swf

Codec & camera12 formats

.av1.avchd.divx.f4v.hevc.m2v.mjpeg.mpeg-2.mxf.ts.wtv.xvid

Size

Keep1080p720p480p

Quality

HighBalancedSmall file

Sound

KeepMonoRemove

Frame rate

Keep30 fps24 fps

Length

Whole videoFirst 30 sFirst 10 s

Common · container · since 2001.mp4checked on load

MPEG-4 Part 14 on the ISO base media format. The safest choice when a file has to play anywhere.

file you getvideo.mp4

containermp4

videoH.264 (x264) (if in build)

soundAAC

best forWeb, phones, social, sharing

this browser plays itmaybe

command it runs

ffmpeg -i input.mp4 -map 0:v:0 -map 0:a:0? -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -c:v libx264 -preset veryfast -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k -ac 2 -f mp4 -movflags +faststart video.mp4

no files yetboltConvert to .mp4

Results, read back by the enginefolder_zipDownload all as ZIP

from · downloadDownload

~/the-safari-question

Ship WebM first, MP4 as the backup.

Every modern browser plays WebM, but some older iPhones and Macs only play MP4. The safe pattern is to list both: the browser takes the first one it can play. We give you both files and the code to paste.

Include an MP4 fallbackFor iPhones and Macs on older versions.Poster imageA still that shows instantly, before the video loads.Don’t preloadSaves data for visitors who never scroll to it.

paste into your pagecontent_copyCopy

<video autoplay muted loop playsinline poster="hero.jpg" preload="none" width="1920">
 <source src="hero.webm" type="video/webm">
 <source src="hero.mp4" type="video/mp4">
</video>

autoplay only works when the video is muted; playsinline stops iPhones from opening it full-screen.

~/see-through-video

A transparent MOV from Final Cut or After Effects? It can stay transparent.

Animated logos and stickers are often exported as MOV with an alpha channel. WebM with VP9 keeps that see-through background on the web; MP4 can't. For Safari, a separate HEVC-with-alpha file is the fallback.

NEW

Original MOV (ProRes 4444)transparent · 38 MBEditing-quality file with an alpha channel. Far too large for a web page.

NEW

WebM (VP9 alpha)transparent · 0.4 MBKeeps the see-through background at a hundredth of the size. Plays in Chrome, Edge and Firefox.

NEW

MP4 (H.264)black backgroundH.264 has no transparency, so the background fills with black. Don’t use MP4 for overlays.

~/other-routes

The other half of the pair, and more.

What people usually need alongside a WebM.

movieMOV to MP4The universal fallback, and for sharing outside the web.IMG_0871.MOVarrow_forward.mp4 · H.264 swap_horizWebM to MP4Going the other way, for editing or iPhone playback.clip.webmarrow_forward.mp4 gif_boxMOV to GIFFor email and places that don’t play video.IMG_0871.MOVarrow_forward.gif · 6 MB

Sources

[1]The video elementSources, autoplay rules and preload.MDN Web Docs ↗[2]WebMThe container and its VP9/AV1 codecs.The WebM Project ↗[3]Transparent video on the webVP9 alpha and HEVC alpha, with a fallback.web.dev ↗

Frequently Asked Questions

Is converting MOV to WebM free?

Yes, MOV to WebM conversion is completely free with no signup, no watermark, and no usage limit. Convert as many files as you need.

Are my files uploaded to a server?

No. The MOV to WebM converter runs in your browser when your file is supported there, so the file stays on your device for that workflow, reducing server exposure for that workflow. Confirm the processing mode before using sensitive content.

How long does MOV to WebM conversion take?

Most MOV to WebM conversions finish in under a minute. Expect a longer wait for a bigger file. It runs on your own device either way, with no account step in front of it.

Will the conversion reduce file quality?

It depends on the pair. Lossless gives you the same thing back, byte for byte. Lossy makes the file smaller and costs you something, though whether you can actually see or hear it is another question.

Does this work on mobile devices?

Yes. The MOV to WebM converter works on phones, tablets, and desktops in any modern browser including Chrome, Safari, Firefox, and Edge.