HEIC & Image Converter

If you have ever moved photos from an iPhone to a Windows PC, you have met .HEIC — Apple's space-efficient format that half the world's software cannot open. This converter fixes that entirely in your browser: drop in HEIC or HEIF files (or TIFF, or any standard image) and convert them to JPG, PNG, WebP, or AVIF, singly or by the batch.

The hard formats are handled with dedicated decoders that load on demand: HEIC and HEIF are decoded with a WebAssembly-based converter, TIFF with its own parser, and everything else through the browser's native image support — so SVG, BMP, and GIF sources work too. On the output side you choose the format and, for lossy targets (JPG, WebP, AVIF), a quality level from 10–100%. Settings apply globally to the batch, and files convert automatically one at a time, with each row showing its result size as it finishes. Download a single file directly, or the whole set as converted-images.zip with original filenames and new extensions.

Everything happens on your device — personal photos never upload to any server, which is precisely what you want when converting a camera roll. Two format notes worth knowing before you pick a target: converting to JPG flattens transparency (the canvas is white-filled), and animated GIFs convert as their first frame — stills in, stills out.

Each file takes the decoding path its format needs: HEIC/HEIF files are converted by a WebAssembly decoder loaded on demand, TIFF files are parsed into raw pixels by a TIFF library, and everything else is decoded by the browser's own image engine. The decoded pixels land on a canvas — white-filled first, so formats without transparency render cleanly — and the canvas is re-encoded to your chosen target via the browser's encoder, with the quality value applied for lossy formats.

The batch runs as a queue: files convert one at a time so the page stays responsive, each row updating as its result lands, and a failed file is marked "Failed" without stopping the rest. Decoded pixels are cached per file, so changing quality re-encodes quickly without re-decoding. AVIF output depends on the browser's encoder support — where the browser cannot encode it, that conversion fails rather than silently substituting another format.

Conversion goes through a canvas, which flattens transparency against white — transparent sources converted to JPG (or any format, given the white fill) lose their alpha channel, and animated GIFs convert as a single first frame. Metadata such as EXIF is not carried into the output. AVIF encoding depends on the browser and fails where unsupported. Very large batches are bound by device memory, and unusual HEIC variants can fail to decode. The quality setting is global; per-file tuning means converting in separate passes.

HEIC/HEIF decoding uses the heic2any WebAssembly library, TIFF uses UTIF (both dynamically imported on first need); other formats decode via the native Image element. Pixels are drawn to a white-filled canvas at source resolution and encoded with canvas.toBlob at quality/100 for lossy targets. The queue processes files sequentially with per-file error isolation and caches decoded canvases so quality changes skip re-decoding. Batch downloads assemble with JSZip client-side; outputs keep the source basename with the new extension.

Choosing an output format

Note the conversion canvas is white-filled, so preserving an alpha channel through this tool is not guaranteed — plan transparent-logo workflows around PNG sources and test the output.

iPhone users whose photos will not open on Windows or older software; web developers producing WebP/AVIF variants; office workers handed TIFF scans; and anyone standardizing a messy folder of mixed formats. For pure size reduction of already-compatible files, the bulk Image Compressor is the simpler tool.