PNG Compressor
Reduce PNG file size directly in your browser while preserving transparency.
Your images
Settings
File limits & compression details
Up to 20 files, 25 MB each and 100 MB per batch. Large images over 25 megapixels are rejected to protect browser memory.
Transparency is retained. When compression produces a larger file, the original PNG is kept.
Never uploaded · processed locally in your browser
Results 0 of 0 done
Your compressed images will appear here.
What is a PNG Compressor?
A PNG compressor reduces the storage size of PNG images. This tool decodes and re-encodes each image inside your browser, removes metadata when the new encoding is smaller, and keeps the original whenever re-encoding would increase its size.
How PNG compression works
PNG stores pixels using filtering and compression. Smart mode reduces the color palette to create a smaller PNG with visually similar quality, while Lossless mode uses the browser's PNG encoder without deliberately reducing colors. Files are processed sequentially, and the original is kept whenever the selected mode produces a larger file.
Lossless vs lossy PNG compression
Lossless mode preserves the decoded image data and may produce modest savings. Smart mode intelligently reduces the palette to improve compression while keeping the image visually similar. Both modes retain PNG transparency and run entirely in your browser.
Does PNG compression reduce image quality?
Lossless mode does not deliberately reduce colors. Smart mode can merge similar colors to produce a smaller palette, so its output is visually similar rather than pixel-identical. Neither mode converts the image to JPEG. Always inspect important output before replacing an original.
Does transparency remain intact?
Yes. PNG alpha transparency is drawn to a transparent browser canvas and encoded back to PNG. The tool never converts the image to JPEG. As with any browser-based image workflow, inspect the downloaded file when exact color-management behavior is critical.
Why PNG files can be large
Detailed images, noise, gradients and very large pixel dimensions can make PNG files difficult to compress. Screenshots, icons and graphics with repeated colors often compress better than photographs. A well-optimized source may show little or no further reduction.
How to reduce PNG file size
Choose Smart for stronger palette-based compression or Lossless to preserve the decoded image data, then select or drop up to 20 PNG files. Review the measured savings and download individual results or the whole batch. The tool never claims a fixed reduction and retains the original whenever no smaller output is achieved.
Example: calculating PNG savings
Illustrative numbers only, not a measured benchmark: a PNG reduced from 1,000 KB to 700 KB saves 300 KB, or 30%: (1,000 − 700) ÷ 1,000 × 100. Actual savings depend on the source and mode. Screenshots and UI graphics with repeated colors often behave differently from detailed photos. Smart reduces the color palette; Lossless does not deliberately reduce colors. Neither guarantees a smaller file, and the tool retains the original when compression is not smaller.
Private, local image processing
Image bytes, filenames, dimensions and file sizes stay in the current browser session. The compressor does not call an upload or image-processing API. Temporary preview URLs are released when a result is removed, the batch is cleared or the page closes.
How to use
- Choose Smart or Lossless compression, then drop PNG files into the upload area or choose Select PNG files.
- Wait while the browser validates and re-encodes each image sequentially.
- Review each result and download it individually, or use Download All for the completed batch.
Frequently asked questions
How do I compress a PNG image?
Drop a PNG into the upload area or select it from your device. Processing begins locally, and the result card shows the original size, output size and savings before you download it.
Does PNG compression reduce quality?
Lossless mode does not deliberately reduce colors. Smart mode reduces the palette for smaller files with visually similar quality. Neither mode converts the image to JPEG, and transparency is retained.
Can I compress multiple PNG files?
Yes. Process up to 20 files in one batch, subject to the per-file and total size limits. Files are handled sequentially to reduce peak browser memory use.
Are my images uploaded to a server?
No. Validation, decoding, re-encoding, previews and downloads happen in your browser. The tool does not send image bytes or filenames to an API or analytics.
Does PNG transparency remain intact?
Yes. The transparent alpha channel is retained during PNG-to-PNG re-encoding. No JPEG conversion occurs.
Why is my compressed PNG not much smaller?
The original may already be optimized, contain complex color patterns or use a palette that cannot be reduced much without a visible change. When the output is not smaller, the tool keeps the original and clearly reports that no reduction was achieved.
Can I compress PNG on mobile?
Yes. Use the file picker to select PNG images available to your mobile browser. Processing speed and memory capacity depend on the device.
Is there a file size limit?
Yes. Each file can be up to 25 MB, each batch can contain up to 20 files and 100 MB, and images above 25 megapixels are rejected to protect browser memory.