PNG Compressor
Shrink a PNG losslessly, or cut its palette when size matters more.
Up to 50 MB per file. Sign up free to compress files up to 100 MB.
| File name | Size | Compress to |
|---|
Checking files and selected compression settings.
This page stops at 50 MB and one file per run. Pro compresses files up to 1 GB and a full batch in one go, with a priority queue.
How to compress PNG files online
PNG uses lossless compression by default, so standard tools barely reduce size. Our engine applies advanced color quantization to achieve much smaller files.
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Upload PNG Images
Select your PNG screenshots, graphics, or logo files. Transparency (alpha channel) is fully preserved during compression. Send several at once, against your daily allowance.
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Choose Compression Level
Select a target size. For PNGs, our tool reduces the color palette from millions to the optimal number of colors, then applies DEFLATE compression for maximum savings.
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Download Optimized PNGs
Download your compressed PNGs with transparency intact. The output remains a valid PNG file, no format conversion needed. ZIP download available for batches.
What this compressor does well
PNG uses the DEFLATE algorithm to compress pixel data losslessly. Row filtering before compression improves ratios for images with repeating patterns.
Reducing a 24-bit truecolor PNG (16 million colors) to an 8-bit indexed palette (256 colors) can shrink file size by 60-80% with minimal visual change.
Unlike JPG, PNG supports full 8-bit alpha transparency per pixel. Our compressor preserves every transparency level, so logos and overlays stay crisp.
PNG files can contain large text chunks, color profiles, and timestamps. Stripping these ancillary chunks alone can shave 10-20% off file size with zero visual impact.
PNG excels at logos, icons, UI screenshots, diagrams, charts, infographics, text overlays, and any image requiring transparent backgrounds or pixel-perfect sharpness.
PNG compression preserves sharp edges and text without the blurring or blockiness artifacts found in lossy formats, making it the best choice for screenshots and diagrams.
Why a tight PNG target costs you resolution
PNG is lossless, so there is no quality dial to turn down, the only way to make one smaller is to store fewer pixels. That makes a tight target riskier than it looks. In our own testing a 2560x1440 screenshot asked for 50KB came back 575x323, small enough that the text was no longer readable, while the same file at 200KB kept a usable 1246x701. If your PNG is a photograph, converting it to JPG or WebP will beat any PNG compression by a wide margin; if it is a flat-colour logo it is probably already small enough to leave alone.
Upload limits worth knowing
The caps people most often run into, and what each one really means in practice.
| Where | Limit | In practice |
|---|---|---|
| Gmail | 25 MB | Attachments above this are converted to a Drive link instead of sending. |
| Outlook.com | 20 MB | Outlook desktop against Exchange is often capped lower, at 10 MB. |
| WordPress (default) | 2 MB | Set by PHP's upload_max_filesize; many hosts leave the default in place. |
| Largest Contentful Paint | under 2.5s | Google treats 2.5s as the good threshold; the hero image is usually what decides it. |
Email attachments are Base64-encoded in transit, which inflates them by roughly 33%. A 20 MB file arrives as about 27 MB, so a 25 MB cap is really closer to 18 MB of actual payload. Leave headroom rather than compressing to exactly the published limit.
How PNG compression works at this target
PNG is lossless, the file format cannot discard image data. To hit small size targets, the compressor has to either (a) reduce the colour palette from 24-bit truecolor to indexed 8-bit (256 colours) or 4-bit (16 colours), which cuts size 40-70% but flattens gradients and can dither smooth areas, or (b) switch encoding to lossy JPG entirely (giving up PNG's transparency and lossless guarantees). For screenshots, diagrams, and logos with limited colours, palette reduction works cleanly. For photographic content saved as PNG, JPG conversion usually gives the best quality-per-kilobyte at this target.
Which target size to pick for PNG
Different portals cap PNG uploads at different sizes. Pick the target that matches where you’re uploading rather than shrinking blindly, over-compressing wastes visible quality, under-compressing gets rejected.