Why in-browser PDF tools beat upload sites
Most "free PDF tools" on the web work the same way: you upload your document to their server, their server does the work, and you download the result. That flow is fine for a flyer — and a terrible idea for contracts, medical records, payslips, ID scans or anything covered by a confidentiality clause. Once a file is uploaded you are trusting a stranger's retention policy, their employees, their logging and their breach record.
PDFLocal flips the model. The two open-source engines that power this page — pdf-lib (writing and restructuring PDFs) and Mozilla's pdf.js (rendering page thumbnails) — both run inside your browser tab. Your file is read into your device's memory, transformed there, and saved straight back to your downloads folder. There is no server-side component at all: this page is a static file. That's also why there are no file-size limits, no daily quotas and no "premium queue" — your own hardware is the only constraint.
How each tool works
Merge: each source PDF is parsed locally and its pages are copied into a fresh document in the order you arranged. Bookmarks and form fields are not carried over (a common limitation of page-copy merging), but page content, fonts and images come through intact.
Split & extract: the pages you select are copied into a new PDF. Choose "one PDF per range" to break a big document into chapters — your browser may ask permission to save multiple files, which is exactly the no-funny-business behaviour you want.
Compress: every page is re-rendered to a canvas at your chosen resolution and re-encoded as a JPEG. This is the same technique scan-optimizer software uses, and it can take a 40 MB scan to 3 MB. The trade-off is honest and unavoidable: pages become images, so selectable text is lost. Keep your original.
Organize: rotation is stored as a page property (lossless), deletion and reordering simply change which pages are copied and in what order. Nothing is re-compressed.
Watermark & page numbers: text is drawn into each page's content stream with standard Helvetica — small, fast and lossless. A watermark added this way is a deterrent, not security: anyone with a PDF editor can remove it, so don't rely on it for secrets.
Practical tips
- Compressing a born-digital PDF (pure text) usually makes it bigger — compression shines on scans and photo decks.
- For email, 100 dpi at quality 65–75 is the sweet spot: readable on screen, comfortably under most 10 MB caps.
- Rotate before you merge — rotation set in Organize survives merging perfectly.
- Password-protected PDFs can't be edited here; remove the password with the owner's tooling first.
New: convert images, extract text & batch-stamp
PDFLocal now does more than restructure existing PDFs — it builds and unpacks them too, all without an upload.
Images → PDF assembles JPG, PNG and WebP files into a single document. Drop a stack of phone photos or scanned receipts, drag them into the right order, and either keep each image at its native proportions (borderless) or place them centred on A4 / Letter pages with a margin you choose. PNGs embed losslessly; other formats are encoded to high-quality JPEG in your browser’s canvas. It’s the fastest way to send a multi-page receipt or a photographed contract as one tidy PDF.
PDF → Images is the reverse: every page is rendered to a crisp PNG or JPG at the quality you pick — screen, high or print resolution. Grab one page for a slide, or download the whole document as a set of images. If your images are heavier than you’d like afterwards, run them through our companion image squeezer, or auto-write alt text with the image describer.
Extract Text lifts the selectable text layer out of born-digital PDFs (exports, Word-to-PDF, saved web pages) so you can copy it or save a .txt file — handy for quoting, search or feeding text into a summarizer. Scanned, image-only PDFs have no text layer, so they’d need OCR, which this lightweight tool intentionally skips.
Batch Stamp (a PDFLocal Pro upgrade) applies one watermark and/or page-numbering scheme — including continuous, zero-padded Bates numbering for legal discovery — across dozens of PDFs in a single pass, with presets you can save and reuse. The free six tools stay free and unlimited forever; Pro simply adds the bulk-processing muscle and a reusable firm stamp. One key (or the All-Access pass) unlocks it on this device, and because there’s no server, your files are never part of the bargain.