About PdfMonster
A free PDF editor that fixes text right where it is — and never sends your file anywhere.
Why we built it
Fixing one typo or one date in a PDF shouldn't mean installing software or creating an account. Most online PDF tools make you upload the file to a server, and sending a document with your name, address or signature to a stranger's server is uncomfortable. On top of that, PDFs often use fonts that are hard to match, so edited text looks out of place.
PdfMonster was started to solve both problems: you don't have to upload anything, and edited text stays as close to the original as we can make it.
How it works
PdfMonster downloads a PDF engine (PDFium, compiled to WebAssembly) into your browser and runs it there. Opening, editing and saving all happen on your own computer. Our server only holds the files that make up the page — HTML, scripts and fonts. Your PDF is never transmitted. You can verify this yourself with your browser's developer tools; see How to use an online PDF editor safely.
What you can do
- Edit text in place — click a line and change it. Font weight, size and spacing are matched to the original, and glyphs already present in the document's font are reused.
- Add annotations — text, rectangles, ellipses, lines, arrows, freehand pen, highlighter and images (PNG/JPEG).
- Redact — text under the box is actually removed from the PDF and covered with a black box.
- Manage pages — rotate, delete, reorder, duplicate, add blank pages, with thumbnails.
- Undo / redo — for text edits, annotations and page operations alike.
Honest limitations
- Text in scanned PDFs (where the text is a picture) can't be edited. We don't support OCR yet.
- In-place text editing isn't available on rotated pages. Annotation tools still work.
- Password-protected or damaged PDFs may not open. Files up to 60 MB are supported.
- If your edit makes a line longer, we squeeze it horizontally by up to 15% to fit, and warn you if it still overflows.
- Characters that the original font doesn't contain are drawn with a substitute font (Noto Sans / Noto Serif), so they may differ slightly from the original.
For important documents, always open the saved file once and check the result.
Open source and fonts
PdfMonster is built on open-source software such as PDFium, HarfBuzz and fontkit, and on the Noto Sans and Noto Serif fonts, released under the SIL Open Font License. See the third-party notices.
Running costs and ads
PdfMonster is free. To cover running costs we may show ads on information pages outside the editor. There are no ads in the editing screen. See the Privacy Policy for details.
Send feedback
If a document looks off after editing, a file won't open, or there's a feature you'd like, tell us on the Contact page. You don't need to send the original file — a description is usually enough.