What is lossless image compression?

Lossless image compression reduces file size without discarding pixel data. When the image is opened again, the pixels are identical to the original.

Yes. PNG uses lossless compression, which makes it good for screenshots, graphics, logos, and images with transparency.

Is WebP lossless better than PNG?

WebP lossless is often smaller than PNG for graphics and images with transparency, but PNG is still more universally accepted by older tools and upload forms.

Can lossless compression make photos much smaller?

Usually no. Photographs have complex pixel variation, so lossless compression often produces large files. For photos, lossy WebP or JPEG is usually better for web use.

Lossless Image Compression: PNG, WebP, and When to Use It

Published June 2026 · A practical guide to reducing file size without losing pixel quality.

Quick answer: Lossless image compression makes an image file smaller without changing any pixels. Use it for screenshots, icons, logos, diagrams, transparent graphics, and images you may edit again. For photographs, lossy WebP or JPEG usually gives much smaller files with little visible difference.

What does lossless image compression mean?

Lossless compression reduces file size by storing repeated or predictable pixel patterns more efficiently. Unlike lossy compression, it does not throw away visual information. When you open a lossless image again, the pixels match the original exactly.

This matters when image accuracy is important: screenshots with small text, logos with crisp edges, UI graphics, charts, medical or scientific images, and source files that will be edited later.

Lossless vs lossy compression

Compression type	Quality	Best for	Common formats
Lossless	Pixels stay identical	Screenshots, logos, diagrams, transparency	PNG, WebP lossless
Lossy	Some image data is discarded	Photos, thumbnails, web images where size matters	JPEG, WebP lossy, AVIF

When should you use lossless image compression?

Screenshots with text: PNG or WebP lossless keeps text edges crisp.
Logos and icons: Flat colors and sharp lines often compress well without quality loss.
Images with transparency: PNG and WebP lossless preserve alpha channels.
Charts and diagrams: Labels and lines stay clean.
Editing masters: Keep a lossless source before exporting a smaller web copy.

When not to use lossless compression

Lossless compression is often a poor choice for photographs on websites. Photos contain lots of detail and color variation, which means PNG files can become several times larger than JPEG or WebP at a visually similar quality. If the image is a normal web photo, resize it and use lossy WebP or JPEG instead.

PNG vs WebP lossless

PNG is the safest lossless format because almost every tool accepts it. WebP lossless can be smaller than PNG, especially for transparent graphics, but some older upload forms and apps still reject WebP. For websites you control, WebP lossless is worth testing. For forms and broad compatibility, PNG is safer.

How to reduce image size without losing quality

Resize the image to the dimensions you actually need.
Use PNG or WebP lossless for graphics, screenshots, and transparency.
Remove metadata when you do not need camera or editing data.
For photos, keep a lossless master but publish a compressed JPEG or WebP copy.

FAQ

Is PNG lossless?

Yes. PNG compression is lossless, so the decoded image preserves the original pixels exactly.

Is WebP lossless?

WebP supports both lossy and lossless modes. WebP lossless is useful for graphics, transparency, and screenshots.

Does lossless mean smaller?

Not always. Lossless files can be large for photographs because no visual data is discarded.

Can I compress a JPEG losslessly?

You can optimize JPEG metadata and encoding without changing pixels, but major size reductions usually require lossy compression or resizing.