Convert HEVC to AVI — Free Online Tool
Convert HEVC/H.265 video files to AVI format by re-encoding the video stream to H.264 (libx264) and the audio to MP3 — making modern, highly-compressed HEVC footage compatible with legacy Windows software, older media players, and editing tools that predate H.265 support.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
HEVC and AVI are fundamentally incompatible at the container and codec level, so this conversion requires full re-encoding of both streams. The H.265 video is decoded frame-by-frame and re-encoded using libx264 (H.264) at CRF 23, which is a well-balanced quality setting for H.264. Since HEVC commonly stores audio in formats like AAC or AC-3 that AVI handles inconsistently, the audio is transcoded to MP3 using the LAME encoder at 128k bitrate — a format that AVI has supported reliably for decades. Because H.264 is less compression-efficient than H.265, expect the output AVI file to be noticeably larger than the source HEVC file at equivalent visual quality. HDR metadata present in HEVC sources will also be lost, as the AVI container and H.264 codec combination does not support HDR.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version of this tool, FFmpeg runs entirely as WebAssembly (FFmpeg.wasm) — no data leaves your device. The same command can be run locally on any desktop with FFmpeg installed for files over 1GB. |
-i input.hevc
|
Specifies the input file, which is an HEVC/H.265 raw bitstream or container file. FFmpeg will demux the video stream and any audio streams present in this source before re-encoding them for the AVI output. |
-c:v libx264
|
Sets the video encoder to libx264, which re-encodes the H.265 video stream into H.264. This is necessary because the AVI container does not support HEVC video, making re-encoding unavoidable for this conversion. |
-c:a libmp3lame
|
Uses the LAME MP3 encoder to transcode the audio stream. MP3 is selected here because it has the longest history of reliable support within AVI containers and will play back correctly on virtually any software or hardware that can open AVI files. |
-crf 23
|
Sets the Constant Rate Factor for the libx264 H.264 encode to 23, which is the libx264 default and represents a good balance between visual quality and file size. Because H.264 is less efficient than the H.265 source, the output file will be larger than the input even at this setting. |
-b:a 128k
|
Sets the MP3 audio bitrate to 128 kilobits per second. This is a widely accepted standard for perceptually transparent MP3 audio for most content types, and is the appropriate default for AVI/MP3 output destined for broad compatibility. |
output.avi
|
Specifies the output filename and, by its .avi extension, tells FFmpeg to use the AVI container format (with OpenDML extension support for files over 2GB). The combination of H.264 video and MP3 audio inside AVI maximizes compatibility with legacy players and editing software. |
Common Use Cases
- Making drone or action camera footage shot in H.265 compatible with older Windows video editors like Windows Movie Maker or early versions of Sony Vegas that lack HEVC support
- Preparing HEVC clips for playback on legacy smart TVs, Blu-ray players, or set-top boxes whose firmware only supports H.264 within AVI containers
- Delivering video files to clients or colleagues whose organizations use older Windows workstations that cannot install modern codec packs
- Converting HEVC recordings from newer security cameras or dashcams into AVI format for ingestion into legacy surveillance management software
- Re-packaging HEVC content into AVI for use with older video analysis or scientific visualization software that was compiled against AVI/H.264 libraries
- Archiving HEVC home videos into AVI/H.264 for long-term storage on systems where broad playback compatibility across old hardware is the priority over file size
Frequently Asked Questions
This is expected. H.265 (HEVC) was specifically designed to achieve roughly twice the compression efficiency of H.264 — meaning it delivers equivalent visual quality at about half the bitrate. When you re-encode to H.264 inside AVI at CRF 23, the encoder requires more data to represent the same image information. A file that was 1GB as HEVC might become 1.5–2.5GB as AVI/H.264, depending on the content. If file size is critical, you can raise the CRF value (e.g., to 28 or 30) to reduce the output size at the cost of some visual quality.
No. HDR (High Dynamic Range) metadata — including HDR10 static metadata or Dolby Vision profiles — is not supported by the AVI container or the libx264 encoder. When HEVC HDR content is re-encoded to H.264/AVI, the HDR metadata is stripped and the video is treated as standard dynamic range (SDR). The actual pixel values may appear washed out or overly bright on SDR displays unless tone mapping is applied, which this basic conversion command does not perform. If your source is HDR, consider adding a tone-mapping filter before doing this conversion.
Only partially and unreliably. HEVC files typically carry audio in AAC, AC-3, DTS, or Opus — none of which have universal or well-standardized support inside the AVI container. This is why the conversion command explicitly transcodes the audio to MP3 using libmp3lame, which is the most historically compatible audio format for AVI. Attempting to copy modern audio codecs directly into AVI would likely produce files that fail to play on many devices or players.
Adjust the -crf value to control H.264 video quality. CRF operates on a scale where lower numbers mean higher quality and larger files, and higher numbers mean lower quality and smaller files. The default is 23. For near-transparent quality use CRF 18; for a smaller file with acceptable quality for web or preview use CRF 28–30. For example: ffmpeg -i input.hevc -c:v libx264 -c:a libmp3lame -crf 18 -b:a 128k output.avi. You can also increase audio bitrate from 128k to 192k or 320k for higher-fidelity audio if your source has good audio quality.
Yes, using a shell loop. On Linux or macOS, run: for f in *.hevc; do ffmpeg -i "$f" -c:v libx264 -c:a libmp3lame -crf 23 -b:a 128k "${f%.hevc}.avi"; done. On Windows Command Prompt, use: for %f in (*.hevc) do ffmpeg -i "%f" -c:v libx264 -c:a libmp3lame -crf 23 -b:a 128k "%~nf.avi". Note that because this conversion requires full re-encoding of H.265 to H.264, batch processing is CPU-intensive and will take significantly longer than container-only remux operations.
No. The AVI container does not support embedded subtitles or chapter metadata, so any subtitle tracks or chapter points present in the HEVC source file will be dropped during conversion. If you need to preserve subtitles, consider converting to MP4 or MKV instead, both of which support subtitle streams. For HEVC sources with subtitle tracks, FFmpeg will typically issue a warning that the subtitle stream cannot be written to AVI and will skip it automatically.
Technical Notes
This conversion involves a full transcode of both the video and audio streams — there is no stream copying possible since HEVC video is not a valid codec within the AVI container, and AVI's audio codec support is largely limited to MP3, PCM, and a few legacy formats. The libx264 encoder used here produces H.264 Baseline/Main/High profile output, which carries none of the H.265-specific features: no 10-bit depth by default (libx264's standard build outputs 8-bit), no HDR, no 360° metadata, and no support for HEVC's Range Extensions. If your HEVC source is 10-bit (common in HDR, film, or high-quality streaming encodes), libx264 will automatically dither down to 8-bit during encoding, which can introduce subtle banding in gradients. The AVI container itself has a 2GB size limit in its original specification, though most modern software uses the OpenDML AVI extension that removes this limit — FFmpeg outputs OpenDML-compliant AVI by default. Multiple audio tracks in the source are not preserved; only the first (or default) audio track is included in the output.