Compress PNG images online.

What does this PNG compressor do?

This tool compresses PNG images using optimized filter strategies and maximum deflate compression. PNG supports transparency — which sets it apart from JPEG. A PNG image can have a fully transparent background (alpha channel), making it the standard format for logos, icons, screenshots, and UI elements. PNG compression is lossless by default, meaning every pixel stays identical to the original. Our compressor also offers a lossy mode that uses colour quantization to reduce palette size, which can dramatically shrink PNG files that contain photographic content.

For example, a 1920x1080 screenshot of a web page might be 2-4 MB as a PNG. Lossless compression can reduce that to 1.2-2.5 MB with identical pixel data — no quality loss at all. For a PNG photograph (say, a product image with a transparent background), lossy compression can cut the file by 60-80% with minimal visible change, because the encoder reduces colour precision where it won't be noticed — preserving edges and gradients while compressing smooth areas.

When to use PNG compression

PNG is the right choice for any image that needs crisp edges, text legibility, or transparency. Use cases include: logos and brand assets that sit on coloured backgrounds, screenshots of software and websites, UI elements like buttons and icons, images with text overlays, and product photos with removed backgrounds. Compression is essential for these assets because PNGs are inherently larger than JPEGs — what would be a 200 KB JPEG is often a 1-2 MB PNG.

If your image does not need transparency and contains smooth gradients (like a photograph), our JPEG compressor will produce smaller files. For modern browsers, WebP offers the best of both worlds — small file sizes with full transparency support.

Benefits of PNG compression

Transparency preserved: The alpha channel is fully maintained — no white backgrounds or broken edges. Lossless option: Perfect for design assets where pixel-level fidelity is non-negotiable. Quantization savings: Lossy mode can cut PNG file sizes by 60-80% for photographic content. Metadata stripping: Remove gamma info, colour profiles, and text chunks that bloat file size. Batch processing: Compress hundreds of PNGs at once with parallel web workers.

Supported formats

Our compressor accepts JPEG, PNG, WebP, AVIF, GIF, SVG, HEIC, and TIFF as input. Output is optimized PNG. All processing happens in your browser — no files are ever uploaded to a server.

Privacy and speed

All PNG compression runs locally in your browser via WebAssembly. Your images never touch a server — not even for a moment. Processing is parallelized across CPU cores: 50 PNG screenshots can be compressed in seconds. There are no file size limits beyond your device's available memory, and no registration is required.

Tips for best PNG compression results

Use lossless mode for UI assets, logos, and screenshots where every pixel matters. Switch to lossy mode for PNG photographs — the palette reduction is barely visible but saves significant space. Enable metadata stripping to remove unnecessary chunks (gAMA, sRGB, text). For images with large uniform areas, PNG already compresses well; our encoder's filter optimization finds the best per-row prediction method to squeeze out additional savings. If you need to resize your PNGs, try our image resizer before compressing for best results.

Palette optimization: 24-bit vs 8-bit PNG

One of the most effective compression techniques for PNG is reducing the colour depth from 24-bit (16.7 million colours) down to 8-bit (256 colours) or lower. This is called palette optimization or colour quantization. For images with a limited colour range — icons, logos, flat illustrations, diagrams, and screenshots of code — the visual difference between 24-bit and 8-bit is often imperceptible, yet the file size reduction can be 50-75%. A 24-bit icon set totalling 1.2 MB may shrink to under 300 KB after palette optimization with zero visible degradation. Our lossy mode applies this technique automatically, analysing the image to build an optimal palette that preserves edges, dithers smooth areas, and discards unused colours. The result is a PNG that looks identical to the untrained eye but loads significantly faster.

Real-world bandwidth savings: Consider an e-commerce site with 50 product thumbnails, each a 24-bit PNG at 400 KB — that is 20 MB of PNG images per page load. After lossless compression, those 400 KB files drop to roughly 200 KB each, cutting the page to 10 MB. Apply lossy palette reduction on suitable images (icons, badges, simple graphics) and the average drops further to 120 KB per image — just 6 MB total. For a site serving 100,000 page views per month, that is the difference between 2 TB and 600 GB of monthly bandwidth. On a CDN costing $0.08/GB, this represents a cost saving of roughly $112 per month, with no perceptible quality loss for visitors. The same principle applies to mobile app assets, email signatures, ad creatives, and any other scenario where PNGs are served at scale.

PNG in web design vs photography: In web design, PNG is the go-to format for anything requiring transparency, sharp text, or exact pixel alignment — buttons, nav icons, hero section graphics, and product cutouts. A photography portfolio, by contrast, rarely benefits from PNG because photographs contain smooth colour gradients that PNG's filtering algorithm handles inefficiently compared to JPEG or WebP. A 2 MB JPEG photograph re-saved as PNG balloons to 8-12 MB with no visible improvement. The rule of thumb: use PNG when your image has hard edges, text, transparency, or fewer than a few hundred unique colours. Use JPEG, WebP, or AVIF for photographs, gradients, and natural scenes. Our compressor makes it easy to identify which assets truly need PNG and which can be converted to more efficient formats — just examine the preview and file size comparison before downloading.

How to compress a PNG — step by step

1. Drop your image. Drag a PNG onto the upload area or click to browse. 2. Choose a mode. Lossless for pixel-perfect output or lossy for maximum savings. 3. Preview. Check that transparency and edges look correct with the comparison slider. 4. Download. Save individually or as a ZIP.

Need to convert your PNGs to JPEG for photographs? Use the image converter. Want to crop icons or UI elements to exact dimensions? Try the image cropper.