What is PDF editing?

PDF editing modifies an existing PDF file by adding or replacing text, inserting images and shapes, drawing annotations, redacting content, and reorganizing pages. Browser-based editors like PDF AI Tools let you change a PDF directly without converting it to Word first or installing desktop software.

Edit PDF Online Free

Add text, images, annotations, highlights, signatures, shapes to any PDF. Free, browser-based, no Adobe Acrobat needed. Instant download.

About Edit PDF

Edit PDF is a full in-browser PDF editor with a 12-tool palette: text (6 fonts, 16 sizes), freehand drawing (7 stroke widths, 5 opacity levels, 12 colors plus highlights), shapes (rectangle, circle, line, arrow), highlights (5 colors), sticky notes, image insertion, and whiteout. It's built on pdf-lib for document structure and pdfjs-dist for page rendering, with an LRU cache that holds the 5 most-recently-viewed pages in memory so flipping through a 100-page document stays smooth. The canvas scales to devicePixelRatio (capped at 2.0) for HiDPI screens, so text stays sharp on retina displays.

Unlike PDF readers with basic annotation tools, this editor is truly non-destructive — every text, shape, highlight, and image you add is stored as a separate overlay object, not burned into the page bytes until you click Save & Download. There's a full undo/redo history stack and a per-page Clear button. Keyboard shortcuts match Adobe's convention (V select, H hand, T text, P pen, R rectangle, E circle, L line, A arrow, G shapes, U ruler, S sticky note, N notes, W whiteout, I image), so anyone used to Acrobat or Preview can get productive in under a minute.

How to Use Edit PDF Online Free

  1. Step 1: Drop your PDF into the editor. Pages render in seconds via pdfjs-dist — even 200-page documents scroll smoothly thanks to the LRU cache.
  2. Step 2: Pick a tool from the left palette (or press a keyboard shortcut: T for text, P for pen, R for rectangle, etc.)
  3. Step 3: Click and drag on any page to add your annotation. Use the top toolbar to change color, font size, stroke width, or opacity.
  4. Step 4: Use Undo (Ctrl+Z) or the per-page Clear button to revert mistakes — nothing is permanent until save
  5. Step 5: Click Save & Download. pdf-lib bakes all your annotations into a new PDF and triggers the download. Your original file on disk is untouched.

Key Features

How We Compare

Compared to desktop alternatives like Adobe Acrobat Pro (starting at $19.99/month), Smallpdf ($12/month for unlimited), or iLovePDF ($9/month Premium), PDF AI Tools delivers comparable quality at $0 for the core feature set. We skip the subscription friction by processing most operations directly in your browser with WebAssembly — no server infrastructure costs to pass on to users. Our AI features (summarization, chat, OCR) use a pay-as-you-go backend that keeps your total cost well under $5/month even for power users.

Frequently Asked Questions

How do I add text to an existing PDF?

Press T (or click the Text tool), pick a font and size from the top toolbar, click anywhere on the page, and start typing. Drag the text box to reposition, resize by dragging its corners. The text is added as a non-destructive overlay — the original page content is preserved byte-for-byte underneath.

Can I edit existing text inside a PDF, or only add new text on top?

This editor overlays new text, shapes, and highlights on top of the page — it does not edit the underlying text flow (PDFs store text by position, not as editable paragraphs, so true in-place text editing requires rebuilding the page). For rewriting original content, use our PDF to Word tool, edit there, and export back to PDF.

Does editing the PDF change the original file on my computer?

No. The file you uploaded is never modified. All edits live in browser memory until you click Save & Download, which creates a new PDF with your annotations baked in. The original stays exactly as it was.

What's the Whiteout tool for?

It places a white rectangle on top of content you want to hide — useful for redacting sensitive information, covering up old text before adding new text, or hiding watermarks you have rights to remove. Note: whiteout is a visual overlay, not true redaction. For permanent removal of sensitive data use the Redact tool in the PDF Redactor.

Can I undo an edit or remove an annotation I added by mistake?

Yes. Ctrl+Z (or the Undo button) removes the most recent edit. Ctrl+Y (or Redo) restores it. Per-page Clear wipes all annotations on the current page. Nothing is permanent until save.

Why are the fonts limited to Helvetica, Times, Courier, and a few script fonts?

PDFs require embedded fonts to render reliably across devices. Loading arbitrary system fonts would need font-licensing checks and significantly larger output files. The 6 included fonts cover standard serif/sans/mono/script needs and embed cleanly via pdf-lib's built-in font subsystem.

Who Uses This Tool