Compress PNG Online

Reduce PNG file sizes by up to 70% while keeping transparency intact — all in your browser, no upload, completely free.

Compress PNG Free →Free · No signup · No upload

PNG files are essential for logos, screenshots, and any image that requires a transparent background — but they can be surprisingly large. An unoptimised PNG logo might be 500 KB when it could easily be under 100 KB with proper compression. Resizor lets you compress PNG files online with lossless or lossy options, directly in your browser, without uploading your images to any server.

Resizor's PNG compressor uses WebAssembly (wasm-vips) for efficient, high-quality compression. Lossless compression preserves every pixel while removing redundant data. For maximum savings, the lossy mode reduces the colour palette — often cutting file sizes by 50–70% with minimal visible difference for most graphics. Transparency (alpha channel) is always preserved. Batch compression is supported so you can optimise a whole folder of PNGs at once.

How It Works

Upload Your PNG

Drop one or more PNG files into the tool. Transparent PNGs (PNG-24, PNG-32) are fully supported.

Choose Compression Level

Select lossless compression to preserve every pixel, or lossy (palette reduction) for maximum size reduction.

Download Compressed PNG

Save your optimised PNG — often 30–70% smaller — with transparency intact.

Why Choose Resizor?

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Privacy First

Your PNG files never leave your browser. Compression runs locally via WebAssembly (wasm-vips).

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Transparency Preserved

Alpha channel transparency is fully preserved during compression — no white backgrounds added.

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Batch Compress

Drop multiple PNGs at once and download all compressed files as a ZIP.

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Free & No Watermark

No account required, no watermarks, no file limits. Completely free.

Frequently Asked Questions

How do I reduce PNG file size without losing quality?

PNG supports lossless compression, which removes redundant data without changing any pixels. You can also reduce the colour depth (e.g. from 24-bit to 8-bit palette) for graphics with fewer colours, saving up to 70% with minimal visual impact.

Why are PNG files so large compared to JPEG?

PNG uses lossless compression to preserve every pixel, whereas JPEG uses lossy compression that discards some data. For photos, JPEG is much more efficient. For graphics, logos, and screenshots with sharp edges or transparency, PNG is usually the better choice.

Does compressing a PNG reduce transparency?

No. Resizor preserves the alpha channel (transparency) when compressing PNG files. Your transparent backgrounds and semi-transparent effects will remain intact.

Should I convert PNG to WebP instead?

For web use, yes — WebP lossless is typically 26% smaller than PNG. Resizor can convert your PNG to WebP lossless while preserving transparency.

Can I compress PNG screenshots in bulk?

Yes. Drop multiple PNG files into Resizor and they'll all be compressed in one batch. Download individually or as a ZIP file.

Compress PNG Online — Start Now

100% free, runs in your browser. No signup required.

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