Because the expensive part — the server farm — does not exist. Processing runs on your device, so the site can stay free without a signup wall in front of it or an upsell in the middle of a job.

Which file types does Lossless PNG Optimization accept?

The drop area takes PNG. Files are read from your device in the browser, so the format has to be one a browser can decode — that is why the accepted list on this page is finite and honest rather than "everything".

What can't Lossless PNG Optimization do?

Browser canvas re-encoding is near-lossless (visual pixels kept). Dedicated bit-level optimizers (optiPNG/pngcrush) run server-side. That limit is stated on the page and in the alert above the tool, not buried in a footnote.

What do I get back from Lossless PNG Optimization?

The result is PNG, offered as a download the moment the work finishes. Multiple results come back together rather than as fifty separate save dialogs.

Lossless PNG Optimization

Beta

Pixel-perfect PNG size reduction.

Browser canvas re-encoding is near-lossless (visual pixels kept). Dedicated bit-level optimizers (optiPNG/pngcrush) run server-side.

Drag & drop images to compress

or click to browse — .png · up to 50 files

PNG re-encoding keeps pixels identical (canvas deflate may differ from the original encoder). Bit-level optimizers like oxipng squeeze a few percent more server-side.

Add at least one image.

Loading tool…

About Lossless PNG Optimization

The job of Lossless PNG Optimization is narrow on purpose: pixel-perfect PNG size reduction. It takes PNG and produces PNG. What it does today: browser canvas re-encoding is near-lossless (visual pixels kept).

Reach for it when getting image file size down is a one-off rather than a workflow: one file, one result, no account in front of it.

How to use Lossless PNG Optimization in 3 steps

Drop the picture on the page — PNG, up to 50 at a time.
There is nothing to configure for Lossless PNG Optimization — the PNG is re-encoded with the pixels kept.
Press Compress image and download the PNG result.

What you get with Lossless PNG Optimization

Batch up to 50 files, returned together
Nothing to configure — drop the file and press the button
Honest scope: browser canvas re-encoding is near-lossless (visual pixels kept).
Runs in your browser — the file is never uploaded
Free to use, with no signup and no account
No watermark or logo added to your output
Works on desktop and mobile, no install

Lossless PNG Optimization: questions

Why is it free?: Because the expensive part — the server farm — does not exist. Processing runs on your device, so the site can stay free without a signup wall in front of it or an upsell in the middle of a job.
Which file types does Lossless PNG Optimization accept?: The drop area takes PNG. Files are read from your device in the browser, so the format has to be one a browser can decode — that is why the accepted list on this page is finite and honest rather than "everything".
What can't Lossless PNG Optimization do?: Browser canvas re-encoding is near-lossless (visual pixels kept). Dedicated bit-level optimizers (optiPNG/pngcrush) run server-side. That limit is stated on the page and in the alert above the tool, not buried in a footnote.
What do I get back from Lossless PNG Optimization?: The result is PNG, offered as a download the moment the work finishes. Multiple results come back together rather than as fifty separate save dialogs.