Free PDF Editor — Annotate PDFs Online

A PDF editor lets you modify PDF documents — but the term covers a wide range of capabilities. Full-featured editors like Adobe Acrobat Pro allow you to rewrite text, rearrange pages, and alter the document structure. Annotation tools, like this one, focus on adding new content on top of the existing PDF: text notes, highlights, drawings, shapes, and arrows.

For most real-world tasks, annotation is exactly what you need. Reviewing a contract? Highlight key clauses and add margin notes. Grading a paper? Draw circles around errors and type feedback. Marking up a design? Drop arrows pointing to specific areas with text comments. Over 2 billion PDF files are in active use globally, and the vast majority of edits people need are annotations, not structural changes.

Our tool renders your PDF page by page, overlays a drawing canvas, and lets you place annotations with precision. When you download, every annotation is permanently embedded into the PDF using the same coordinate system — so your markup appears identically in any PDF viewer, on any device.

Step 1: Upload your PDF. Drag and drop your file into the upload area, or click to browse. Files up to 50 MB are supported. Your file stays in your browser — nothing is uploaded to any server.

Step 2: Navigate to the page you want to annotate. Use the Prev/Next buttons or type a page number directly. Adjust the zoom level for comfortable viewing — Fit Width works well on most screens.

Step 3: Choose an annotation tool. Select Text to type notes, Highlight to mark sections, Draw for freehand markup, or use Rectangle and Arrow for precise callouts. Each tool has color and size options in the toolbar.

Step 4: Place your annotations. Click or drag on the page to create annotations. Use the Select tool to click an existing annotation and change its color or delete it. Undo and Redo buttons let you fix mistakes.

Step 5: Download the annotated PDF. Click "Download Annotated PDF" to generate a new file with all your annotations permanently embedded. The original file is never modified.

The Text tool lets you click anywhere on the page and type. You can choose font sizes from 12pt to 36pt and pick any color. Press Enter to place the text. Text annotations are rendered using Helvetica for clean, professional appearance in the final PDF.

The Highlight tool creates semi-transparent rectangles at 30% opacity — click and drag to highlight sections of text or images. This is the fastest way to call attention to important content without obscuring it.

Freehand Draw turns your mouse or finger into a pen. Choose a color and stroke width (1-5px), then draw freely. This is ideal for circling content, underlining, or adding informal markup that feels natural and immediate.

The Shape tools include four options: Rectangle for boxing content, Circle for enclosing areas, Arrow for pointing to specific elements, and Line for underlines or connections. All shapes support custom color and stroke width from 1-5px.

The Stamp tool provides one-click status stamps: Approved, Rejected, Draft, Reviewed, and Confidential. Each stamp appears as a bold bordered label in your chosen color — essential for document review workflows. Students and professionals annotate an average of 15+ PDFs per month, and stamps speed up routine approvals significantly.

The Eraser removes annotations one at a time — click on any annotation to delete it. You can also select an annotation with the Select tool and press Delete or Backspace. Every action supports Undo (Ctrl+Z) and Redo (Ctrl+Shift+Z), so you can experiment freely without worry.

Adobe Acrobat Pro costs $19.99/month — $240 per year for a tool most people use occasionally. It offers full text editing, OCR, e-signatures, and form creation. If you need those advanced features daily, it may be worth it. But if you primarily need to annotate, highlight, and mark up PDFs, you are paying for capabilities you never use.

Other paid alternatives like Foxit PDF Editor ($8/month), Nitro PDF Pro ($12/month), and PDF Expert ($80/year) offer similar feature sets at lower prices. Online tools like SmallPDF and iLovePDF offer free tiers, but restrict usage to 1-2 tasks per day and upload your files to their servers.

Our tool is genuinely free — no daily limits, no file size caps, no watermarks, no account. More importantly, your files never leave your device. Every PDF you annotate stays in your browser's memory and disappears when you close the tab. For privacy-sensitive documents — contracts, medical records, financial statements — this is a significant advantage over server-based tools.

The tradeoff is clear: if you need to rewrite existing text, merge form fields, or perform OCR on scanned documents, you need a full editor. For everything else — adding notes, highlighting, drawing, marking up — this free tool delivers the same result without the subscription.