MUTools

PDF

PDF Sign & Annotate

PDF Sign & Annotate lets you sign, write on, and mark up a PDF right in the browser. Switch between three tools on one screen — a freehand pen, text annotations, and a highlighter marker — to sign contracts, fill out application forms, and review or proofread documents, all in one place.

Drag & drop a PDF here

or

PDF supported (up to 100 MB per file). Encrypted PDFs cannot be loaded.

Every PDF is processed entirely in your browser and never sent to a server.

Handwritten signatures are inserted as an image. This is not a legally binding digital signature backed by a certificate.

About PDF Sign & Annotate

PDF Sign & Annotate lets you sign, write on, and mark up a PDF right in the browser. Switch between three tools on one screen — a freehand pen, text annotations, and a highlighter marker — to sign contracts, fill out application forms, and review or proofread documents, all in one place.

The pen draws freehand with a mouse, finger, or stylus, so you can add a handwritten signature, sketch a check mark, or jot a note. The text tool works by clicking where you want the text and typing — any language, including Japanese, Chinese, and Korean, is drawn with your browser's fonts and baked into the PDF, so there is no font-embedding to configure. The marker highlights lines with a translucent stroke, perfect for calling out the important parts. Multi-page PDFs are supported, and you can move between pages as you annotate.

Every PDF you load is processed entirely in your browser — nothing is uploaded to a server. Contracts, quotes, and documents containing personal information stay on your device. There's no sign-up and no watermark, and you can download the annotated PDF on the spot. Runs entirely in your browser.

How to use

  1. Drag & drop a PDF onto the dropzone, or click to choose one (up to 100 MB per file).
  2. Pick "Pen", "Marker", or "Text" in the toolbar, then set the color, width, or font size.
  3. Drag on the page with the pen or marker to draw and highlight. For text, click where you want it and type.
  4. On multi-page PDFs, move between pages with "‹ ›" to annotate. Use "Undo / Redo" for the last action, or "Clear page" to wipe that page's annotations.
  5. Click "Apply annotations & download" and the annotated PDF downloads automatically.

Use cases

  • Business users who need to add a handwritten signature to a contract, order form, or consent form and send it back.
  • Filling out government, school, or other PDF forms by adding text to the required fields, then submitting them.
  • Reviewing documents and reports, highlighting with the marker while writing comments by hand.
  • Designers and engineers adding handwritten notes or instructions to drawings, designs, or scanned documents.
  • Signing or annotating a PDF with a stylus on a tablet or phone.

Notes

  • A handwritten signature is inserted into the PDF as an image. It is not a legally binding digital signature backed by a certificate (PKI), so use a dedicated e-signature service when legal validity is required.
  • Annotations are baked into each page as a high-resolution image layer. Pages you don't annotate keep their original quality.
  • Encrypted (password-protected) PDFs cannot be loaded. Remove the password first, then load the file.
  • The limit is 100 MB per file. Very long PDFs depend on your browser's available memory.
  • No watermark is added. Every PDF is processed entirely in your browser and never stored on a server.

FAQ

Are PDFs uploaded to a server?
No. Loading, annotating, and exporting all happen entirely in your browser, so contracts and documents with personal information are safe to use here.
Is a handwritten signature legally binding?
This tool inserts your handwritten signature into the PDF as an image; it is not a digital signature backed by a certificate (PKI). That's plenty for internal sign-offs or consent forms, but for contracts that require legal validity, use a dedicated e-signature service.
Can I add text in other languages?
Yes. Text annotations are drawn with your browser's fonts and then baked into the PDF, so Japanese, Chinese, Korean, and other scripts come through as-is, with no font-embedding to configure.
Can I handwrite on a phone or tablet?
Yes. The pen and marker support handwriting with a finger or stylus, so you can sign or jot notes on a PDF from a tablet.
Is it free? Is there a watermark?
It's completely free with no sign-up, and the PDF you download carries no watermark.
Can I edit annotations after adding them?
Before you download, you can undo and redo your actions. Text can be moved with its grip and removed with the × button. Once the PDF is downloaded, annotations are baked into the page and can no longer be edited.