Compress PNG Online

Compress PNG images in your browser using real color quantization — the same technology behind TinyPNG and Google's Squoosh. Compress PNG Online uses UPNG.js to reduce PNG palette size from 16 million colors down to 8–256, achieving 40–70% size reduction while preserving sharp edges and full transparency.

Unlike tools that just change the zlib compression level (which barely reduces PNG size), this tool actually performs lossy color quantization: it finds the optimal set of N colors to represent your image, dramatically reducing file size with minimal visible quality loss. Drop any number of PNGs, use the compress level to balance quality vs size, and preview every image in the before/after split viewer before downloading.

Transparency is fully preserved. Logos, icons, and any PNG with alpha channel compress correctly. If compression would make a file larger (e.g., already-optimized simple graphics), the original is automatically kept. Convert to WebP for even better compression on modern browsers.

• Color quantization (like TinyPNG) — real lossy PNG compression via UPNG.js palette reduction, not just zlib tuning
• Transparency preserved — alpha channel kept intact through quantization; logos and icons compress without visual artifacts
• 100% browser-local — Canvas API + UPNG.js client-side, no upload, works offline after first load
• Unlimited batch — drop hundreds of PNG files with per-file progress and savings display
• No-gain protection — if compressed output is larger than original, original file is kept automatically
• WebP conversion — convert PNG to WebP for 25–50% extra savings; WebP also supports transparency
• Smart resize — set max width/height with aspect-ratio lock; resizing is often the fastest way to cut PNG size
• Before/After split viewer — drag divider and zoom to inspect color quantization quality before downloading
• Batch ZIP download — download all compressed PNGs in one archive with a single click

1. Drop PNG files. Drag PNGs onto the drop zone, or click Browse. Unlimited files accepted.
2. Set compress level. Lower = more colors = larger file but better quality. Higher = fewer colors = smaller file. The badge shows the level (e.g., "Balanced · 25%"). Check the before/after preview to confirm quality.
3. Choose output format. PNG preserves transparency universally. WebP gives 25–50% better compression and also supports transparency (for modern browsers).
4. Optional: resize. Enter Max Width/Height to scale the image down. Resizing combined with quantization gives maximum size reduction.
5. Compress. Click Compress All. Images are processed with UPNG.js color quantization. If UPNG is still loading, a fallback compresses via canvas resize only.
6. Download. Individual files via the download icon, or grab all in a ZIP.

Example 1 — Website icons and logos: 20 PNG logo variations (avg 120 KB each) → compress level 20, PNG output, transparency preserved → avg 45 KB each → 62% savings → download ZIP.

Example 2 — App screenshots: iOS/Android screenshots (avg 1.2 MB each) → compress level 40, max width 800 → avg 180 KB each → 85% savings → individual download per screen.

Example 3 — Convert PNG to WebP: Product images with transparency → compress level 15, WebP output → avg 60% smaller than PNG → sharper on retina displays, faster page loads.

• TinyPNG-quality, zero cost — color quantization runs entirely in your browser with no account, no limits, and no per-image fee.
• Transparency safe — alpha channel is preserved through all compression and format conversion operations.
• Honest output — if compression makes a file larger, the original is kept automatically; you never get a "compressed" file that's actually bigger.