Video to WebM Converter

How to Convert Video to WebM Online

1. Upload Your Video: Click "+ Add Files" or drag and drop to add a video. Accepted inputs include MP4, MOV, AVI, MKV, WMV, FLV, MTS, M2TS, MPG, MPEG, 3GP, TS, VOB, HEVC, AVCHD, OGV, RM, XVID, and 30+ other formats. Batch conversion is supported.
2. Pick Codec, Quality Preset, and Bitrate: Default output is VP9 at the Very High preset, which is web-optimized for most use cases. Open Advanced Options to switch File Compression mode between Quality Preset, Specific file size, Constant Bitrate, Variable Bitrate, Constant Quality, or Constraint Quality. Audio defaults to Opus (recommended over Vorbis for new content).
3. Resize and Trim (Optional): Under Video resolution, choose Keep original, a Preset Resolution (4K, 1440p, 1080p, 720p, 480p, 360p, 240p, 144p, plus social aspect ratios like 1080x1920 and 1080x1350), Resolution Percentage, or set custom Width x Height. Use the Trim section to pick Unchanged or a Time Range with HH:MM:SS.ms precision.
4. Convert and Download: Click Convert. processing runs on our servers — no sign-up, no watermark, no file count limit.

Why Convert to WebM?

WebM is an open container format Google released in 2010, built on the Matroska structure with VP8 or VP9 video and Vorbis or Opus audio (AV1 is also supported by compliant decoders per the W3C media-format spec). It is the format the HTML5 <video> element was designed around, and at equivalent visual quality VP9 typically produces files 20-30% smaller than H.264 MP4 — material savings on high-traffic sites.

• HTML5 background and hero videos — drop a WebM into a <video autoplay loop muted playsinline> block as the primary source with an MP4 fallback. Smaller payloads mean faster Largest Contentful Paint and lower CDN bills.
• Replacing GIFs on the open web — converting a 5 MB animated GIF to a looping WebM regularly yields a sub-500 KB file with cleaner color and no dithering. Discord, Twitter/X, and most modern forums autoplay the <video> tag inline.
• Telegram video stickers and emoji — Telegram's sticker pipeline requires WebM specifically: VP9 codec, no audio, 30 FPS cap, 3-second duration cap, 512 px on one side (100x100 for custom emoji), and 256 KB max post-encoding per the Telegram core spec.
• Royalty-free distribution — VP8, VP9, Vorbis, and Opus are all open and royalty-free, removing the H.264/H.265 patent-pool concerns that apply to commercial MP4 distribution at scale.
• Smaller asset bundles for PWAs and mobile web — VP9 + Opus is the lightest mainstream combo for short product loops, onboarding tours, and demo clips on data-conscious mobile audiences.
• Archive sources from camcorders, screen recorders, and phones — re-encode AVCHD/MTS, MOV, AVI, FLV, or MKV captures into a single WebM master for browser-native review without proprietary players.

WebM Codec Choice — VP8 vs VP9 vs AV1

Default to VP9 unless you have a specific reason to choose otherwise. Pick VP8 only when a downstream tool requires it (Telegram explicitly requires VP9 for video stickers — VP8 is rejected).

WebM vs MP4 — Container Trade-offs

Use both with the <video> element multi-source pattern — browsers pick the first they understand:

<video autoplay loop muted playsinline>
  <source src="clip.webm" type="video/webm">
  <source src="clip.mp4" type="video/mp4">
</video>

If you need the reverse direction afterwards, use WebM to MP4; to shrink an existing file without re-containerising, see Compress WebM; to make a static-frame loop instead, WebM to GIF.

Frequently Asked Questions

What input video formats can I convert to WebM?

MP4, MOV, AVI, MKV, WMV, FLV, MTS, M2TS, MPG, MPEG, MPEG2, M4V, 3GP, 3GPP, 3G2, TS, VOB, HEVC, AVCHD, OGV, RM, RMVB, ASF, DV, F4V, MXF, DVR, SWF, XVID, DIVX, CAVS, and more — most camcorder, screen-recorder, and phone capture formats are accepted.

Should I pick VP9 or AV1 for web video?

VP9 for almost everything in 2026 — it has wider hardware-decode support on phones and faster encoding. Choose AV1 only when bandwidth is critical and you control the playback environment (newer Chrome, Firefox, Edge, recent macOS/iOS Safari). AV1 encode times can be 5-10x VP9 for similar quality settings.

Does Safari support WebM yet?

Yes. Safari 16 and later (macOS Ventura, iOS 17.4 and later) play VP8/VP9 WebM natively. For Safari 14 and earlier, ship an MP4 <source> as a fallback inside the same <video> tag.

Will WebM autoplay in Discord, Telegram, and Twitter/X?

Yes — modern Discord and Twitter/X embed and autoplay WebM in <video> containers, and Telegram uses WebM as its native video-sticker and video-emoji format. Note that Telegram requires VP9 specifically (not VP8), no audio track, max 30 FPS, max 3 seconds, max 256 KB after encoding, and 512 px on one side for stickers (100x100 for emoji).

Why is my WebM smaller than the original MP4?

VP9 and AV1 are newer-generation codecs than the H.264 commonly used in MP4. At the same Constant Quality target, VP9 typically delivers a 20-30% smaller file and AV1 another 20-30% beyond that, with no visible quality loss. If you want the file even smaller, increase the CRF/Quality value or lower the resolution preset.

How do I make a Telegram WebM video sticker?

Upload your clip, set codec to VP9, resolution to 512 (one side) with the aspect ratio preserved, use the Trim section to cap duration at 3 seconds, set frame rate to 30 FPS or lower, and target a Specific file size under 256 KB. Telegram rejects stickers with audio, so strip the audio track during conversion.

Can I keep the original audio quality?

Yes. Choose Opus (recommended for new WebM content — better compression and quality at low bitrates) or Vorbis (the original WebM audio codec, still widely compatible). Both are royalty-free. Set audio bitrate to 128 kbps for music, 96 kbps for general speech-and-music mixes, or 64 kbps for voice-only.

Why does the WebM project page mention only VP8 and VP9, but you say AV1 works?

The original WebM container spec from Google in 2010 defined VP8 (later VP9) plus Vorbis/Opus as the mandatory codecs. AV1 was added later as an optionally-supported video codec — current MDN and W3C media-format documentation list AV1 inside WebM as supported by compliant implementations. In practice every browser that ships AV1 will play it inside a .webm container.

Can I batch-convert a whole folder of videos to WebM?

Yes. Add multiple files in step 1 and they will share the same codec, quality, resolution, and trim settings. Each file produces its own WebM output for download.