Convert PNG to JXL
Encode PNG images as JPEG XL with transparency-aware lossless and lossy options.
Private by default
The codec runs on this device. The image is not posted to an upload endpoint.
About this png to jxl
Converting PNG to JPEG XL can reduce storage for screenshots, illustrations, and transparent assets while retaining alpha. Lossless mode keeps decoded pixels exact; lossy mode is better for complex photographic PNGs where a modest visual tradeoff is acceptable.
The encoder reads the PNG into an RGBA buffer inside a worker. Large source dimensions still require significant memory, so the tool checks pixel count before allocating the full image rather than trusting the extension alone.
Graphics and screenshots often respond differently from photographic PNGs, so the page exposes lossless and lossy choices instead of one unexplained compression level. Alpha is carried into the encoder when present. Each file is decoded independently, checked against the pixel limit, and compared with its own output rather than using a generic savings estimate.
How it works
- 1Choose one or more compatible files or paste an image from the clipboard.
- 2Review the detected format and options, then start the local processing job.
- 3Check the result details and download the new file, extracted data, or generated package.
Example use cases
- Handle png to jxl without creating an account or installing desktop software.
- Inspect or prepare PNG files before sharing them with another person or service.
- Keep private file contents out of a remote conversion queue.
Supported formats and limits
- Accepted input
- PNG
- Maximum file size
- 100 MB per file
- Batch processing
- Up to 25 files
- Processing location
- On this device
Limitations
- Lossy mode changes decoded pixel values even when the source PNG was lossless.
- Animated PNG behavior is not promised; the supported path treats the selected PNG as a still image.
- Very large transparent canvases can require several RGBA buffers and may exceed mobile-browser memory.
Why use this tool
- The real tool appears before supporting content, so the task starts immediately.
- Heavy code is loaded only for this utility and work is moved off the main interface where practical.
- Results use the bytes actually produced or detected—never a predicted size or fake success state.
Frequently asked questions
Is my file uploaded to a server?
The codec runs on this device. The image is not posted to an upload endpoint.
Should a PNG logo use lossless or lossy JXL?
Lossless is the safer starting point for flat colors, sharp edges, text, and reusable artwork. Lossy encoding is more suitable for photographic PNG files after visual inspection.
Is PNG transparency retained in JPEG XL?
The encoder receives RGBA pixels and can retain alpha in the supported still-image path. Confirm the alpha status in the result before replacing an original asset.
Why was my file rejected even though the extension looks correct?
The contents may be empty, corrupt, too large, or a different format that was renamed. Re-export the original file from its source app and try again.
Does this work on phones?
Yes in current Chrome, Safari, Edge, and Firefox where the required browser or WebAssembly feature is available. Large jobs may complete more reliably on a device with more memory.