Convert images to JPG, PNG or WebP
Change the format of one image or a whole batch — for example WebP to JPG or PNG to WebP — without sending them anywhere.
Runs on your device · 0 bytes uploaded
Drag files to reorder, or use the arrows.
How to convert Image
- Add one or more images.
- Choose the format you need.
- Click “Convert images” and download the result.
Private by design — and you can check
Your files are never uploaded, because there is nowhere to upload them to.
- No upload step existsFiles are read and written inside this browser tab. There is no server that could receive them.
- The browser enforces itThis page’s Content Security Policy only allows connections back to this site, which serves nothing but the app itself.
- See for yourselfOpen developer tools, watch the Network tab and run a job: no request carries your document.
- Open sourceEvery line is on GitHub, built on qpdf, pdf.js and pdf-lib.
Frequently asked questions
Are my files uploaded anywhere?
No. ZapDoc does the work inside your browser tab, using open-source engines compiled to WebAssembly and JavaScript. Your file is read from your device, processed locally, and the result is saved straight back to your device. You can check this yourself: open your browser’s developer tools, go to the Network tab, and run a job — no request carries your file.
Which format should I choose?
JPG for photos that must open everywhere, PNG for screenshots and graphics that need sharp edges or transparency, WebP for the smallest files on the web.
Is ZapDoc free?
Yes. There is no sign-up, no watermark and no daily limit. ZapDoc is open source under the MIT license.
More private tools
- Compress ImageMake JPG, PNG and WebP images smaller.
- Resize ImageMake images larger or smaller, by pixels or percent.
- Image to Text (OCR)Select and copy text from any photo or screenshot.
- PNG to JPGConvert PNG images to JPG in bulk.
- JPG to PNGConvert JPG images to PNG in bulk.
- WebP to JPGConvert WebP images to JPG in bulk.
- JPG to WebPConvert JPG images to WebP in bulk.
- Merge PDFCombine several PDFs into one, in the order you choose.