Compress PNG Online – Lossless with OxiPNG, Free

Drop images here or browse files

JPG, PNG, WebP · up to 30 images · you can also paste with Ctrl+V

Quality: 75%70–80% is ideal for websites.

Output formatPNGs are optimised losslessly with OxiPNG; WebP or AVIF give the biggest savings.

Max width in px (optional)Larger images are scaled down.

Target size in KB (optional)Each image is saved just under this size.

Pre-set for you: Output format is Same as original and no target size is set, so PNG files stay PNG and are optimised losslessly. Leave the quality slider alone: it does not affect PNG. For other options open the full Image Compressor.

How lossless PNG compression works

A PNG stores pixels exactly, so the only way to shrink it without changing the picture is to store the same pixels more cleverly. OxiPNG tries different filter strategies and compression settings, removes unnecessary metadata and keeps whichever encoding is smallest. The image you download is pixel-for-pixel identical to the one you added.

How much you save depends on how the PNG was made. Screenshots and exports from apps that do not optimise can shrink by half or more, while PNGs that were already optimised may only lose a few percent. If the result would not be smaller, Tolket keeps your original.

How to compress PNG files

Drop one or more PNG files in the box above, or paste a screenshot with Ctrl+V.
Leave Output format on Same as original.
Press Compress images and download the results, or grab them all as a ZIP.

Lossless PNG or a different format?

Your image	Best choice
Logo, icon or UI screenshot that must stay pixel-perfect	PNG (this page)
Photo saved as PNG by mistake	Convert PNG to JPG: often 5–10 times smaller
Website graphic with transparency	WebP: keeps transparency, much smaller
Upload form with a KB limit	Set a target in the 100KB compressor

Tips

Reduce the dimensions first if the PNG is bigger than it will ever be shown. Set a maximum width above and the image is scaled down, then optimised.
Screenshots of text compress best when they are not scaled; keep them at their original size where you can.
Need a tiny file for a form? PNG cannot hit an exact KB size. Setting a target size switches the output to JPG.

Frequently asked questions

Does lossless compression reduce quality?

No. Every pixel, including transparent ones, stays exactly the same. Only the way the data is packed changes.

Is this the same as TinyPNG?

No. Services like TinyPNG reduce the number of colours, which is lossy. Tolket’s PNG mode is lossless. For much smaller files, convert to WebP instead.

Are my PNG files uploaded?

No. OxiPNG runs in your browser as WebAssembly, so screenshots with private information never leave your device.