---
title: "Compress PNG Online — Private, No Upload | Compress Pro"
description: "Compress PNG images in your browser — fully lossless or with smart color reduction, resizing and target file size. No uploads, no accounts. Free and private."
canonical: https://compress-pro.com/compress-png
---

# Compress PNG images.

> Lossless or lossy — your PNGs never leave your browser.

Compress PNG images right in your browser. Keep it fully lossless, or allow smart color reduction for dramatically smaller files that still look sharp. **Nothing is uploaded — files stay on your device.** Free to use, with no ads, no sign-up and no daily limits.

**No uploads · No ads · Free & open source.**

## How it works

1. Drop files anywhere on the page, click to browse, or paste with Ctrl/⌘ + V.
2. Pick a quality or preset — or set an exact target size and let the tool find it.
3. Compress, compare before/after, and download — individually or as a ZIP.

## Lossless vs lossy PNG

At quality 100 pixels are untouched: metadata is stripped and the data is simply repacked more efficiently — a true lossless pass, typically 10–30% smaller. Below 100, colors are first reduced to an optimized palette, which routinely cuts 60–80% on screenshots and UI graphics with no visible difference.

## What shrinks, and by how much

| Source | Expected saving |
| --- | --- |
| Screenshots & UI graphics | 60–80% with the lossy palette |
| Logos and icons | 30–60% |
| Photos saved as PNG | 50–80% — or convert to JPG/WebP |
| Already-optimized PNGs | A few percent, lossless |

## When WebP beats PNG

PNG is the right format for pixel-perfect graphics that must stay lossless. But if the image is going on a web page, WebP holds the same picture — transparency included — at a fraction of the size. The [PNG to WebP](https://compress-pro.com/png-to-webp) converter keeps transparency intact; for photos that ended up as PNG by accident, [PNG to JPG](https://compress-pro.com/png-to-jpg) is the bigger win.

## Under the hood

Two engines share the work here. At quality 100, OxiPNG repacks your PNG losslessly — same pixels, tighter bytes. Below that, libimagequant takes over: it is the palette-quantization engine inside pngquant, the tool famous for cutting screenshots 60–80% with no visible change. Both are compiled to WebAssembly, so every pass runs entirely on your device.

## Frequently asked questions

### Is it safe to compress private images here?

Yes. The pixels are decoded and re-encoded right in your browser — images are never uploaded, and the server does nothing but deliver this page. Close the tab and no trace of your photos remains. Want proof? Run one file through, switch your connection off, and run another — it still works. Compressing also strips hidden metadata — EXIF, GPS location and camera details never reach the output.

### Is PNG compression lossless or lossy?

Both, your choice. At quality 100 pixels are untouched — pure lossless. Below that, colors are reduced to a smaller, optimized palette first, which is much smaller and usually indistinguishable for screenshots and graphics.

### When should I convert a PNG to WebP or JPG instead?

PNG is best for graphics, screenshots and anything needing transparency. For photographic content, converting to JPG or WebP via the output format option is usually far smaller.

### Can I target an exact file size?

Yes — target-size mode finds the strongest compression that fits under a limit you set, and you can cap dimensions to downscale large screenshots.

## Related tools

- [Convert PNG to WebP](https://compress-pro.com/png-to-webp)
- [Convert PNG to JPG](https://compress-pro.com/png-to-jpg)
- [Compress JPG images](https://compress-pro.com/compress-jpg)
- [Compress SVGs](https://compress-pro.com/compress-svg)

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Part of [Compress Pro](https://compress-pro.com/) — every tool page has a markdown twin at `<page url>.md`. Full tool index: [llms.txt](https://compress-pro.com/llms.txt)