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All processing for this tool happens in your browser. Your input is not sent to a server.
About this tool
Convert supported local HEIC/HEIF and raster images to PNG, JPEG, WebP or real AVIF.
Common uses
- Convert a local HEIC photo for a website that accepts AVIF.
- Export a transparent logo, or disable transparency to fill its background white.
How to use it
- 1.Choose a supported local image, then select PNG, JPEG, WebP or AVIF.
- 2.For AVIF, set quality from 10 to 100 and choose whether to preserve transparency; encoding runs locally.
- 3.Inspect the verified result and download the matching format. Cancel and clear can stop a pending encode.
Limits and notes
- Local HEIC/HEIF decoding: one file at a time, 30 seconds per phase. Up to 20 MiB per file, 4096 pixels per edge and 8 million pixels; batch: 20 files / 80 MiB / 32 million decoded pixels, 64 MiB total results.
- HEIC exports the primary image with container rotation/mirroring/crop applied. Sequences are rejected. Other animated raster inputs become one static browser frame. Original EXIF, HDR and color profiles are not preserved. Decoder download is about 2 MiB; processing requires workers, WebAssembly and OffscreenCanvas.
- AVIF uses a local single-thread encoder downloaded only when you select AVIF (about 3.4 MiB, same origin). AVIF output is limited to 2048 pixels per edge, 4 million pixels, 16 MiB and 30 seconds; Cancel and clear stops its worker.
- AVIF quality is 10–100. Values below 100 use lossy RGB encoding; 100 uses lossless encoding of the decoded 8-bit pixels sent to the encoder. Alpha is encoded losslessly when transparency is preserved; disabling transparency fills white. Browser decoding and canvas compositing can change RGB values, especially under transparency, so this does not preserve the original file exactly. Output is static; Worker, WebAssembly and browser AVIF decoding are required. Original metadata, HDR and color profiles are not retained.
Frequently asked questions
What does this tool do?
Convert supported local HEIC/HEIF and raster images to PNG, JPEG, WebP or real AVIF.
Decoder licenses, corresponding source and replacement instructions
The unmodified LGPL decoder and exact corresponding source are available from the license link. HEVC patent clearance depends on the deployment and jurisdiction; no universal patent license is claimed.
What does AVIF quality 100 preserve?
At 100, this encoder uses lossless encoding for the decoded 8-bit pixels it receives, with lossless alpha when transparency is enabled. Browser decoding and canvas compositing can change pixels, including RGB under transparency; the original file, metadata, HDR and color profiles are not preserved. Values below 100 use lossy RGB encoding. Compare quality 20 and 90 on a detailed image and inspect the preview and file size.