Why is PNG compression different?
PNG is a lossless format — the standard encoder stores every pixel exactly as-is, with no quality trade-off. That makes PNG great for screenshots, icons, and graphics that need pixel-perfect accuracy, but it also means naive re-encoding produces a file the same size or larger. To actually shrink a PNG, you need palette quantization: analysing the image colors and reducing them to a smaller set of up to 256 representative values. The output is still a valid PNG file, transparency is preserved, and the file size drops dramatically — often 60–80% — because fewer unique colors means the lossless compression inside PNG has far less work to do.
This is the same technique used by tools like TinyPNG. The difference here is that everything runs in your browser — your files never leave your device.
How to compress a PNG file
- Drop your files — drag PNG images onto the upload zone, click to browse, or paste from clipboard. Up to 30 at once.
- Set the quality — 80% keeps 204 palette colors and looks near-identical for most logos and icons. Lower for aggressive savings on simple graphics; higher for detailed illustrations.
- Click Compress — the tool quantizes each PNG using palette reduction. Your files stay on your device.
- Check the savings and download — each file shows its before and after size plus the percent saved. Download individually or grab them all as a ZIP.
How much smaller will my PNG get?
Results depend entirely on image content. The fewer unique colors in the original, the more dramatic the savings:
| Image type | Typical saving at 80% | Visible change |
|---|---|---|
| Icon / logo (flat colors) | 70–90% | None to minimal |
| UI screenshot | 50–70% | None on solid areas, slight softening on fine text |
| Illustration with gradients | 40–60% | Banding visible at aggressive settings |
| Photograph saved as PNG | 30–50% | Color posterization at lower settings |
For photographic content, converting to WEBP or JPEG is usually more effective than palette quantization. Reserve PNG compression for graphics that need the PNG format.
Choosing the right quality setting
The quality slider maps to palette size: 100% = 256 colors (near-lossless), 1% = 2 colors (extreme). In practice:
- 85–100% — Safe for anything with gradients, detailed artwork, or fine text. Small savings but quality fully intact.
- 70–85% — Sweet spot for logos and UI assets. Large savings, change rarely visible at normal sizes.
- 50–70% — Aggressive. Works well for flat-color icons and simple graphics. May show color banding on gradients.
- Below 50% — Only for thumbnails or cases where size is the absolute priority and quality is secondary.
PNG compression for websites and apps
PNG is the default format for icons, logos, UI elements, and any graphic that needs a transparent background. These assets are typically loaded on every page — a 200 KB logo that could be 30 KB is a permanent tax on load time. Compressing your PNG assets before shipping can cut Core Web Vitals LCP times significantly for image-heavy pages.
For Next.js, React, and other modern frameworks, also consider the sharp pipeline or next/image optimization, which applies server-side compression automatically. This tool is useful for assets that bypass that pipeline — favicons, Open Graph images, and manually referenced static files.
PNG compression for WordPress
WordPress uploads go through the media library and are re-compressed by the server using whatever image library is installed (GD or ImageMagick). PNG handling in WordPress is often poor — it defaults to lossless mode and produces large files. Pre-compressing your PNGs before upload ensures the version stored in /wp-content/uploads is already optimised, regardless of server configuration. Pair with a plugin like Smush or ShortPixel to cover previously uploaded images.
PNG vs WEBP — when to use each
If your platform supports WEBP, converting PNG to WEBP almost always wins on file size: WEBP supports full transparency, delivers 30–50% smaller files than optimised PNG, and is supported by all modern browsers. Use PNG when:
- The target platform requires PNG (some email clients, older apps, app store assets)
- You need maximum compatibility with legacy software
- The image will be further edited and re-saved (PNG is lossless; no generational loss)
For web delivery where format flexibility exists, try the PNG to WEBP converter — you will almost certainly get a smaller file than palette quantization alone can produce.
Compressing PNG vs compressing JPEG
JPEG compression works by reducing encoding precision for all spatial frequencies — it is applied uniformly across the image. PNG compression via palette quantization works by reducing the number of distinct colors. The two techniques suit different content: photographs are better served by JPEG or WEBP (continuous tones, many colors), while logos, icons, and UI assets with flat fills and sharp edges benefit most from palette reduction. To compress a JPEG file, use the dedicated JPEG Compressor. To handle a mixed batch of formats, Image Compressor covers JPG, PNG, and WEBP together.
Privacy
Every byte stays in your browser. Compression runs using a JavaScript library called UPNG — there is no server, no upload, no temporary file. Your PNG images never leave your device.