ImageAlchemyCompression Studio

Shrink PNG files — free lossless PNG optimization

Reduce PNG file size without losing a single pixel. OxiPNG-grade re-encoding keeps full transparency and quality while stripping wasted space. Private, free, batch processing.

When to use PNG

PNG is the right choice for flat-color graphics, logos, screenshots, diagrams and images with hard transparency — anything where pixel-perfect lossless quality matters. It's the wrong choice for photographs, where WebP at quality 80 looks identical at a fraction of the size.

How PNG optimization works

PNG is always lossless, so a PNG optimizer can't throw pixels away. Instead it re-filters and re-encodes the data more efficiently: better delta filters per scanline, stronger zlib/DEFLATE compression, and removal of unused palette entries and metadata chunks.

OxiPNG: the modern PNG optimizer

OxiPNG is a Rust-based optimizer that tries multiple filter and compression strategies and keeps the smallest result — often 15–40% smaller than a standard PNG export, with zero quality loss. ImageAlchemy uses it under the hood.

PNG vs WebP lossless

WebP's lossless mode beats PNG by roughly 20–30% on the same content. If you don't strictly need the PNG format, convert flat graphics to WebP lossless. Keep PNG when you need universal compatibility or you're embedding the image somewhere WebP isn't accepted.

How to compress a PNG with ImageAlchemy

1. Drop your PNG files. 2. Keep PNG as the output format (or try the Max Quality preset). 3. Compress — OxiPNG optimization runs automatically. 4. Download individually or as a ZIP. Up to 200 images per batch, fully on-device.

Related guides

WebP compressorJPEG compressor9 ways to reduce image file sizeWhat is lossless compression?

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Frequently asked questions

Use a lossless optimizer like OxiPNG, which re-filters and re-compresses the data to produce files 15–40% smaller with zero quality loss. Also strip metadata chunks and reduce color depth to a palette when the image has 256 colors or fewer.

Yes. PNG is a lossless format, so all real PNG optimization is lossless — it improves filtering and DEFLATE compression rather than discarding pixel data. Any tool that visibly degrades a PNG isn't optimizing, it's converting.

PNG stores every pixel losslessly, which is extremely inefficient for photographs with millions of colors. For photos, use WebP or AVIF at quality 80 — visually identical and 5–10× smaller. Reserve PNG for flat-color graphics and hard transparency.

OxiPNG is a modern PNG optimizer written in Rust. It tries multiple filter and zlib compression strategies per image and keeps the smallest result, achieving 15–40% reduction with no quality loss. ImageAlchemy uses it for its PNG output.

WebP lossless supports full alpha transparency and is roughly 20–30% smaller than PNG for the same content. Use WebP when the platform allows it; keep PNG where you need maximum compatibility (email, legacy systems, document embedding).