Step 1: Submit your AVI files using the button above or by pull and release.
Step 2: Click the 'Transform' button to start the transformation.
Step 3: Save your converted WebM files.
AVI to WebM Transformation FAQ
How do I re-encode AVI to WebM without quality loss?
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Upload your AVI file and our converter applies a CRF-based re-encode targeting visually-lossless WebM output (CRF 18 by default, lower = larger / higher quality). The codec is chosen to match the WebM container (H.264 / H.265 / VP9 / AV1 as appropriate).
Which codec does the WebM output use?
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It depends on the container. MP4 defaults to H.264 (broadest playback support); MKV and WebM default to H.265 and VP9 respectively for better compression at the same quality. You can override codec choice in the advanced options before conversion.
Will my audio track survive AVI to WebM conversion?
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Yes — audio is re-muxed (when AVI and WebM share an audio codec) or re-encoded to AAC / Opus / Vorbis depending on what the WebM container supports. Multi-track audio (commentary, alternate languages) is preserved.
Can I keep the original framerate when converting AVI to WebM?
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By default, framerate is unchanged (AVI 24fps stays 24fps in WebM). If you need to change it (e.g. interlaced 29.97 → progressive 30fps), use the framerate option, which handles 3:2 pulldown and deinterlacing in the same pass.
What is the file size difference between AVI and WebM?
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Same-codec re-muxes (e.g. AVI → WebM where both use H.264) produce nearly-identical sizes. Codec changes can swing the size dramatically: H.264 → H.265 typically halves the file at the same visual quality; H.264 → VP9 is roughly comparable.
Will the WebM file play on iPhone / Android / Smart TV?
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MP4 / H.264 plays natively everywhere. MOV / H.264 plays on Apple devices and most Smart TVs but not on older Android. MKV needs VLC on iOS. The advanced options include a "device compatibility" preset that picks the safest codec / container combination for the target device.
How long does converting a 1-hour AVI file to WebM take?
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It depends on the codec change. Same-codec re-mux: 30-60 seconds (no re-encode). Re-encode to a different codec: typically 0.3-0.7x source duration on our GPU pipeline, so a 1-hour file finishes in 18-40 minutes.
What is the max resolution supported for AVI to WebM?
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Up to 8K (7680×4320) on Premium. Free users are capped at 4K (3840×2160) per the file-size limit. HDR metadata (HDR10, Dolby Vision) is preserved where both AVI and WebM containers support it.
Is my AVI video private during conversion?
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Yes — uploaded video files are processed in isolated workers and deleted within minutes of completion. We never view, store, retain, or share content. See /privacy/ for the full data retention window.
Can I crop or trim during the AVI to WebM conversion?
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Not in the same step — use /video-trim/ or /video-cutter/ to trim before converting, then queue the AVI → WebM step. Trimming and converting in series is faster than re-encoding the whole file just to crop.
Why is the WebM file blurry / pixelated compared to the AVI source?
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Almost always a bitrate-too-low setting. Re-encoding from a high-bitrate AVI into a lower-bitrate WebM at the default CRF compresses heavily on motion-heavy scenes. Push CRF down to 16-18 (or set explicit bitrate) and re-run to recover quality.
Does the AVI to WebM converter support subtitles?
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Yes — embedded subtitle tracks (mov_text in MP4, SRT/ASS in MKV) are preserved when both AVI and WebM containers support them. Burned-in (hardsub) subtitles transfer automatically because they are part of the video frame.