HEIC to JXL Converter
Convert HEIC to JXL in your browser. HEIC files usually come from iPhones and iPads since iOS 11, and many recent Android phones; JXL is the better fit for archiving and future-proof high quality storage. You get a JPEG XL encoded with libjxl compiled to WebAssembly, lossy at the quality you choose or lossless. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
HEIC expected · other image formats also work
How to use HEIC to JXL
- 1
Add your HEIC files: drop them here, choose them, or paste from the clipboard.
- 2
Set the quality.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .jxl files one at a time or together as a ZIP.
Why use Aback Images for heic to jxl
Where the JXL goes next
JXL opens in Safari 17+, macOS 14 and iOS 17, GIMP, Krita, ImageMagick and the libjxl tools.
JXL next to HEIC
Both formats are lossy, so the size mostly follows the quality setting; at the default the JXL usually lands in the same range as the HEIC.
A second lossy pass
HEIC is lossy already, since it stores lossy HEVC (H.265) intra coding, on iPhones as a grid of 512×512 tiles, so keep the quality at or above the default to avoid stacking a new layer of artefacts on the old one.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
HEIC vs JXL
What changes from HEIC to JXL
Encoding: the HEIC uses lossy HEVC (H.265) intra coding, on iPhones as a grid of 512×512 tiles; JXL uses lossy VarDCT or lossless modular coding; existing JPEGs can be repacked without loss, and the download is a JPEG XL encoded with libjxl compiled to WebAssembly, lossy at the quality you choose or lossless.
Bit depth: 8 or 10 bits per channel in the HEIC; JXL allows 8 to 16 bits per channel, or floating point, and the JXL written here has 8 bits per channel. 10-bit HEIC photos are reduced to 8 bits per channel.
Colour: YCbCr, usually tagged Display P3 on iPhones in the HEIC; JXL supports sRGB, Display P3, linear and other spaces described in the codestream, written here as 8-bit sRGB.
Transparency: the HEIC stores it as an auxiliary image item, rarely used by cameras; the JXL keeps it as an extra channel in the codestream.
Other images: the HEIC can hold a thumbnail, depth map, HDR gain map and burst shots as extra items; only the main image is converted.
Metadata: the HEIC can carry EXIF, XMP and an ICC profile, stored as items; JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders, but nothing is copied across.
About HEIC
HEIC is the default photo format on iPhones and many Android phones. It is about half the size of JPEG, but Windows, many websites and older software cannot open it without converting.
A HEIC is a HEIF file (ISO base media boxes with the brand 'heic'). iPhone photos store the picture as a grid of 512×512 HEVC tiles that the decoder stitches together, with the thumbnail, depth map and HDR gain map as further items.
HEIC files usually come from iPhones and iPads since iOS 11, and many recent Android phones.
About JXL
JPEG XL is a next-generation format designed to replace JPEG. It compresses better than JPEG and WebP, supports lossless, HDR and progressive decoding, and can losslessly repack existing JPEGs.
A JPEG XL file is either a bare codestream starting with FF 0A or an ISO base media container whose 'jxlc' box holds the codestream. A recompressed JPEG keeps a 'jbrd' box that lets the original JPEG bytes be rebuilt exactly.
When converting HEIC to JXL makes sense
JXL is the better choice for archiving and future-proof high quality storage, while HEIC suits storing photos on Apple devices.
JXL strengths: Excellent lossy and lossless compression; Progressive decoding and HDR; Huge image sizes. Drawbacks to weigh: Browser support is limited (Safari only by default); Few apps can open it yet.
Limitations
- HEIC is already lossy, so a second lossy pass should stay at a high quality setting.
- iPhone photos are usually Display P3; colours are mapped to sRGB, so very saturated reds and greens can look slightly less vivid.
- Chrome and Firefox do not display JPEG XL by default, so it is not yet a format for websites; it suits archives and apps that support it.
- Lossless JPEG XL is usually smaller than PNG for the same pixels.
More conversions
Related tools
Convert JXL to HEIC in your browser, a HEIF file with JPEG compression inside. Batch, private, no uploads.
Convert HEIC to JPG in your browser, with transparency filled in a colour you pick. Batch, private, no uploads.
Convert HEIC to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. Batch, private, no uploads.
Convert HEIC to WebP in your browser, ready for images on websites and in apps. Batch, private, no uploads.
Convert JPG to JXL in your browser, ready for archiving and future-proof high quality storage. Batch, private, no uploads.
Shrink JPG, PNG, WebP, AVIF and GIF files with MozJPEG, OxiPNG and modern codecs, with a live before/after preview.
Resize to exact pixels, a percentage or a longest side, with Lanczos3 and Magic Kernel resampling. Batch ready.
Strip EXIF, GPS, XMP, IPTC and comments losslessly. Pixels are never re-encoded for JPG, PNG and WebP.
Frequently asked questions
Does converting HEIC to JXL lose quality?
JXL is lossy, so detail the eye barely notices is discarded to save space. The HEIC was lossy already, so keep the quality high to avoid stacking artefacts. 10-bit HEIC photos are reduced to 8 bits per channel. Not carried over: any a thumbnail.
Is transparency kept in the JXL?
Yes. HEIC stores it as an auxiliary image item, rarely used by cameras, and the JXL is written with an alpha channel, so transparent areas stay transparent.
Why can't I open HEIC photos on Windows or websites?
HEIC uses the HEVC codec, which is patent-encumbered and not built into most browsers, Windows apps and upload forms. Converting makes the photo open where HEIC does not, and the HEIC is decoded inside your browser to do it.
Which apps open JXL files?
Safari 17+, macOS 14 and iOS 17, GIMP, Krita, ImageMagick and the libjxl tools. It opens in Safari 17 and later; Chrome and Firefox do not display it by default.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.