Edit PDF
Add text, highlights, shapes, drawings, and images to any PDF. Browser-only — files never leave your device.
How It Works
Upload your PDF
Drop in any PDF. All pages are rendered as an interactive canvas.
Add your edits
Use the toolbar to add text, highlights, shapes, images, or freehand drawings on any page.
Save and download
All edits are embedded into the PDF and downloaded — original fonts and content untouched.
Why SynthPDF?
Text with font controls
Add text in Helvetica, Times New Roman, or Courier New — choose size, color, bold, and italic. Text is embedded as real PDF text, not an image.
Insert images
Drop a PNG or JPEG onto any page. Position it anywhere — perfect for adding logos, stamps, or diagrams.
Shapes and drawings
Draw rectangles, circles, arrows, lines, and freehand pencil marks in any color and line width.
Browser-only — no upload
Everything runs in your browser. Files never leave your device — safe for confidential documents.
Highlight tool
Drag to highlight any region in yellow, green, blue, or pink.
Instant download
Edits are applied in seconds client-side. No server round-trip — no waiting.
Frequently Asked Questions
You can add new text on top of the PDF in any position, font, size, and color. Editing the original embedded text requires server-side processing — use our PDF-to-Word tool to convert first, then edit in Word.
Yes. All edits are added as a new layer on top of the original PDF content. The existing text, images, and fonts are never modified.
Helvetica, Times New Roman, and Courier New — all with bold and italic variants. These are standard PDF fonts supported by every viewer.
Yes — click the Image tool, select a PNG or JPEG from your device, then click anywhere on the page to place it.
No page limit. Free plan supports PDFs up to 25 MB.
No. All editing runs in your browser using PDF-lib. Your files never leave your device.