This page explains, in plain language, how the tools on PAYATE PDF Tools work, which technology they use, how we test them and what their limits are. We believe you should know exactly what happens to your documents.
1. Everything runs in your browser
When you pick a file, it is read into your browser's memory on your own device. The tool builds the result locally and gives it to you as a download. No file is ever uploaded to our servers or to anyone else. See File Security for how you can verify this yourself.
2. The open-source technology we use
| Library | What it does | License |
|---|---|---|
| pdf-lib | Reads and writes PDF structure: copying, merging, rotating and removing pages, adding text such as page numbers and watermarks. | MIT |
| PDF.js (Mozilla) | Renders PDF pages to images and extracts text. It is the same engine used by Firefox's built-in PDF viewer. | Apache 2.0 |
| JSZip | Packs several result files into one ZIP download and builds Word (.docx) files. | MIT |
| Tesseract.js | Recognises text in scans and photos (OCR), including Arabic. | Apache 2.0 |
These libraries are loaded from the jsDelivr CDN only after you choose a file, so they do not slow down the page for visitors who are just reading.
3. How each tool works
- Merge, split, organize, rotate and delete pages copy the original page objects into a new PDF without re-compressing them, so text stays selectable and quality is unchanged.
- Compress PDF renders every page with PDF.js at a chosen resolution (about 70, 95 or 120 DPI) and stores it as an optimized JPEG. This gives large savings on scans and photos, but text in the result is no longer selectable.
- JPG to PDF draws each image through a canvas so the camera orientation is respected, then places it on a page of the size you choose.
- PDF to JPG renders pages at 96, 150 or 300 DPI and saves them as JPG or PNG.
- Added text (page numbers, watermarks, text to PDF, edit and sign) uses the standard PDF fonts for Latin text, so it stays selectable. Arabic and other scripts are shaped by your browser and embedded as sharp transparent images, so they always display correctly.
- Protect and Unlock PDF use a pdf-lib edition with standard PDF password encryption; unlocking copies the pages into a new, unprotected file after you enter the password.
- OCR PDF uses Tesseract.js (Apache 2.0), an open-source OCR engine that runs in the browser, with language data for English, Arabic and more.
- Redact PDF flattens every redacted page into an image with the black boxes burned in, so hidden text is removed from the file.
- PDF to Text reads the text layer of the PDF with PDF.js and keeps line breaks and page order.
4. How we test
- Every tool is tested with PDFs created by office software, web browsers, scanners and phone apps, from one page to hundreds of pages.
- We check the output by reopening it: page count, page order, rotation, text layer and file size.
- We test on current versions of Chrome, Edge, Firefox and Safari, on desktop and mobile.
- After each update we repeat the tests before publishing.
5. Known limits
- Password-protected PDFs must be unlocked before they can be edited.
- Very large files depend on your device's memory; a computer handles more than an older phone.
- Scanned PDFs contain images, not text, so PDF to Text cannot extract words from them.
- Added Arabic text is embedded as an image, so it cannot be selected or searched in the result.
6. Updates and corrections
If a tool gives a wrong result, please tell us on our contact page with your browser and device. Read our editorial policy for how we handle corrections.