Kratopix Resize, compress and convert images and PDFs — all on your device.

🔒 Your files never leave your device Online 0network requests ✓ Available offline

Presets

Settings

Max width (px)

Max height (px)

Images are only made smaller, never larger.

Crop (centered) File format Quality: 80% Max file size (KB)

If set, quality (and if needed, dimensions) is lowered until the file fits. Not available for PNG.

Drop images here or click to choose JPEG, PNG, WebP, GIF, AVIF — many files at once

How do I know nothing is uploaded?

Disconnect from the internet after the page opens — it keeps working normally.
Install it as an app: it opens and works even with no connection at all.
The “network requests” counter at the top shows the page sends nothing.
The page’s security policy (CSP) forbids the browser from connecting to any server.
Re-encoding strips EXIF metadata, including your photo’s GPS location.

What can I do with Kratopix?

How do I compress a photo or reduce its file size?

Add the image, set “Max file size (KB)” or pick a preset like “Email (under 500 KB)”, then download it. For JPEG and WebP, Kratopix lowers the quality, and if needed the dimensions, until the file fits.

How do I resize an image?

Enter a max width or height in pixels. The image keeps its proportions and is never made larger. You can also crop it to 1:1, 4:5, 16:9 or 3:2.

Can I make a passport or ID photo (35×45)?

Yes. The “ID / passport photo 35×45” preset crops your photo to the right shape for applications and online forms, such as gov.gr.

How do I compress a PDF or turn photos into a PDF?

Open the PDF tab. You can turn images into one PDF (A4, Letter or fit to image), merge several PDFs, compress a PDF to a target size, in color or black and white, or edit a PDF: add text, highlight, draw, white-out, black out or blur parts of a page.

Is it free, and does it work on my phone?

Yes. It is free, with no account and no ads. It works in any modern browser on a phone or computer, and you can install it as an app to use it offline.

Why is it called Kratopix?

Kratopix was called KeepPix until October 2026. The name comes from the Greek “κρατάω” (I keep): your files stay with you.

Is Kratopix open source?

Yes. All of its code is public under the AGPL-3.0 license, so anyone can check that your files never leave your device: github.com/Pnyxus/image-tools

Is there an Android app?

It is coming to Google Play. You can test it now, before everyone else: Become a beta tester