PNG Compressor

Reduce PNG size by downscaling and reducing the colour count.

Drop an image here or click to choose a file

Processed on your device — never uploaded

What Is This Tool?

PNG uses lossless compression, so you cannot simply turn a quality dial. This tool reduces file size two honest ways: by capping the pixel dimensions, and by quantising each colour channel to fewer levels (posterisation), which makes the data more repetitive and therefore more compressible. You can also export to WebP for a much larger saving.

How It Works

Drop a PNG onto the box or choose one.

Set a maximum width, and/or reduce Colours per channel.

Optionally tick Export as WebP for a bigger cut.

Compare the sizes and click Download.

Everything runs locally in your browser — the image you choose is decoded onto an HTML canvas on your own device and is never uploaded to a server.

Features

Width cap that keeps the aspect ratio
Per-channel colour quantisation (posterise)
Optional one-click WebP export
Transparency preserved
All processing is local

Common Use Cases

Shrinking oversized screenshot PNGs
Reducing flat UI graphics and diagrams
Cutting the size of logo and icon files
Preparing PNGs for the web without an external optimiser

Frequently Asked Questions

Why can’t I just lower PNG quality?

PNG has no lossy quality setting — it always stores every pixel exactly. Size only drops if there are fewer pixels or the pixel data is simpler (fewer distinct colours).

What does "colours per channel" do?

It rounds each red, green and blue value to a limited number of steps. Fewer steps means large flat areas of near-identical colour, which PNG compresses better. Too few steps causes visible banding.

How much smaller will my PNG get?

Modest for photos, often large for screenshots, diagrams and flat graphics. Exporting to WebP typically beats any PNG-only saving.

Is transparency kept?

Yes, both for the PNG output and the optional WebP output.

Is anything uploaded?

No. It all happens in your browser.