Convert PNG to JPEG XL online, free

How transparency is preserved

Transparency is the whole reason to choose JPEG XL over a format like JPG when converting a PNG. JPG has no alpha channel and would flatten any see-through area onto white. JPEG XL has a full alpha channel, so the conversion keeps your transparency exactly.

Mechanically, the PNG is decoded and drawn onto a canvas without any white fill behind it, so the empty pixels stay empty. The JPEG XL encoder then writes those transparent regions out as genuine transparency, and a cut-out, sticker, or logo comes back ready to sit on any background.

This makes JPEG XL a real alternative to PNG and WebP for transparent assets, not just for photographs. You keep the see-through edges while cutting the file size that made PNG awkward to ship.

If a destination cannot read JPEG XL but you still need transparency, the answer is PNG or WebP, not JPG. The reverse tool converts a .jxl back to a transparent PNG in your browser whenever you need it.

Lossy versus lossless, and keeping edges crisp

This converter encodes by quality, which is lossy by default. For photographs and soft-edged images that is ideal: you get a large size saving with no visible difference. For flat graphics, logos, and line art, lossy compression can soften the hard edges that PNG kept razor-sharp, so raise the quality when the image is full of crisp boundaries or small text.

JPEG XL also has a true lossless mode that is smaller than PNG while staying pixel-perfect, which is the ideal target for archival graphics. That mode is best produced with the cjxl command-line tool, because a browser canvas works from decoded pixels rather than the controls a lossless encode needs.

A simple rule helps: photographs and detailed images saved as PNG convert beautifully to lossy JPEG XL here, while pure line art or UI mockups that must stay exact are better kept as PNG, or encoded losslessly with a dedicated tool.

Either way, the encode runs locally. The WebAssembly libjxl encoder downloads once and then works entirely on your device, so your assets never leave the browser tab.

Who can open a JPEG XL today

Read this before converting in bulk. On the web, Apple leads: Safari 17 and later, on macOS Sonoma and iOS 17 and newer, decodes JPEG XL natively. Chrome, Edge, and Firefox do not by default, so a .jxl you make may not open in your own browser.

Desktop software is further along. Photoshop, Lightroom and Camera Raw, Affinity, GIMP, Krita, and Paint.NET open JPEG XL, and ImageMagick, FFmpeg and the libjxl tools handle it for developers. Recent Windows 11 builds added support, while older Windows needs a codec add-on.

So JPEG XL shines in a workflow you control, an Apple-centric one, a design or photo pipeline, or a long-term archive, and struggles anywhere you hand a file to an unknown recipient. A transparent .jxl emailed to someone on Chrome will likely not open.

When the image has to open everywhere, keep the PNG or convert the JPEG XL back to one. The point of moving to JPEG XL is efficiency inside a pipeline that can read it, not maximum compatibility.

Good reasons to convert PNG to JPEG XL now

Shrinking PNG photographs is the clearest win. A photo saved as PNG, often by an editor that defaulted to it, is needlessly huge. JPEG XL keeps the look and any transparency while cutting the size dramatically, which is ideal for archives and asset libraries.

Transparent asset libraries benefit too. If you store many cut-outs, icons, or product images with alpha and your tools read JPEG XL, the format keeps the transparency while reclaiming a lot of disk space.

Apple and professional workflows can adopt it now. With Safari 17+, macOS Sonoma+, and editors like Affinity and Krita reading JPEG XL, design teams get its efficiency immediately rather than waiting for universal browser support.

And future-proofing holds: convert from your PNG originals now and you have a modern, royalty-free, transparent file ready for when support widens, with PNG always one conversion away.

Converting a whole folder of PNGs at once

Asset migrations are rarely a single file, so the tool is built for the batch. Drop a folder of PNGs and every file is encoded to JPEG XL in parallel using a worker pool in your browser, with the alpha channel preserved on each, then bundled into a single ZIP with the original names and the new .jxl extension.

Up to 100 files at 50 MB each go in one batch. Detailed and photographic PNGs take a moment each because JPEG XL encoding is heavier than reading a PNG, but the work spreads across your CPU cores rather than queuing one at a time.

Because nothing uploads, batch size is bounded only by your device's memory, not a server quota or a paid tier. There is no per-file fee, no watermark, and no cap on how many batches you run.

Keep your PNGs until JPEG XL opens everywhere you need. You then have the light, modern archive and a universally readable transparent copy side by side, and you can regenerate PNGs by converting the .jxl files back at any time.