What's the best way to compress WebM for Instagram Reels?

Upload your .webm file, pick Instagram Reels as the platform (it's already selected on this page), and compress. We'll target 500 MB to stay safely under Instagram Reels's 650 MB cap. Output is MP4 H.264 that plays inline on Instagram Reels.

Does Instagram Reels accept WebM files directly?

Instagram Reels plays MP4 inline. We convert WebM to MP4 during compression so it displays properly in Instagram Reels's video player.

Will quality drop when compressing to fit?

For short clips under a few minutes, the difference is hard to notice on a phone screen. For longer videos, we scale down resolution (1080p → 720p) before degrading quality at the original size. You can also trim the video to the highlight reel before compressing — that preserves full visual quality in the kept portion.

Do I need an account?

No. Upload, compress, download. Files auto-delete from our servers after 1 hour. No signup, no watermark, no email required.

WebM → Instagram Reels

Compress WebM for Instagram Reels

Instagram's uploader rejects WebM outright — neither the mobile app nor the web interface accept .webm files, regardless of size or duration. This is a hard platform-level block, not a compression issue. WebM is what Loom, browser screen recorders, and Chrome-based tools export by default; if you've ever tried to post a Loom clip to Reels, this is why it fails. This page transcodes WebM (VP8/VP9 video, Opus/Vorbis audio) to MP4 H.264 with AAC audio — the format Instagram actually accepts — and crops/letterboxes to 9:16 vertical at 1080×1920 for Reels.

650 MB targetInput: WebMOutput: MP4 H.264

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Auto-deletedFiles gone in 1 hour

How to compress WebM for Instagram Reels

1Drag your .webm file onto the upload zone above (or browse to it).
2Instagram Reels is already selected — we'll target 500 MB to stay safely under the 650 MB cap.
3Optionally trim to a highlight clip or switch to H.265 for 30-50% smaller files at the same quality.
4Download the compressed MP4 and share it on Instagram Reels. Source file auto-deletes from our servers after 1 hour.

What to know about WebM → Instagram Reels

Instagram's upload dialog gives a generic error for WebM — the file isn't too big, it's unsupported.
Loom's default 'Download video' gives WebM — this page is specifically for that workflow.
Horizontal WebM screen recordings get letterboxed to 9:16; add a background graphic in a separate editor for better aesthetics.
VP9 transcodes to H.264 without visible quality change at Reels bitrates.

The compression math

A 60-second 1080p VP9 WebM screen recording = ~40 MB. Re-encode to H.264 1080×1920 (cropped) at CRF 23 = ~30 MB, well under Instagram's 650 MB cap, ready to upload directly.

About WebM files

WebM is Google's open, royalty-free video format that uses VP8 or VP9 video codecs. It's widely used by browser-based screen recorders (like Loom exports), Chrome extensions, and web applications. While WebM plays natively in Chrome and Firefox, it has poor support on iOS devices and is rejected by most social media platforms. CompressYourVideo.com converts WebM to compressed MP4 (H.264), making it compatible with every device and platform. This is especially common for screen recordings from browser tools, which default to WebM output. The conversion preserves video quality while often reducing file size, since H.264 is more efficient than VP8 at equivalent quality levels.

About Instagram Reels

Compress and optimize videos for Instagram Reels. Instagram Reels supports up to 650MB for videos under 10 minutes, with 9:16 vertical aspect ratio and MP4 H.264 format required.

Related compression tools

Compress any WebM video Compress any format for Instagram Reels

Or compress WebM for a different platform

WebM → WhatsApp WebM → Discord WebM → Email WebM → Telegram WebM → IG Story WebM → TikTok WebM → YT Shorts WebM → Facebook