Is my PDF uploaded to a server?

No. All PDF processing happens entirely in your browser. Your files never leave your device and are never uploaded to any server.

Can I add a digital signature to a PDF?

Yes. Use the Signature tool to draw your signature on any PDF page. You can resize and position it anywhere on the document.

PDF Editor Online Free — Edit Annotate PDF in Browser

📖 How It Works

How to Edit PDF Online Free

Edit, annotate, and sign PDF files in seconds — no software, no signup, 100% browser-based.

Step 01

📂

Upload PDF

Click the upload area or drag and drop your PDF file. Your PDF is processed entirely in your browser — never uploaded to any server.

Step 02

✏️

Add Text & Annotations

Add text anywhere on the page. Double-click to edit inline. Add highlights, sticky notes, strikethroughs, and underlines.

Step 03

🔷

Draw Shapes & Signatures

Add rectangles, circles, arrows, and freehand drawings. Use the signature tool to draw and embed your digital signature.

Step 04

⬜

Redact & Cover

Use the White Cover tool to redact sensitive information. Place white boxes over text or images you want to hide.

Step 05

📥

Download Edited PDF

Click Download PDF to save your edited document. All annotations, text, shapes, and signatures are baked into the final PDF.

💡 Use Cases

Who Uses PDF Editor?

From students to professionals — everyone needs to edit PDFs at some point.

📝

Fill PDF Forms

Add text to PDF forms that don't have fillable fields. Place text boxes precisely over form fields and download the completed form.

✍️

Digital Signatures

Sign contracts, agreements, and documents digitally. Draw your signature and embed it anywhere on any page of the PDF.

🔒

Redact Sensitive Info

Cover personal information, account numbers, or confidential data before sharing documents using the white cover tool.

📚

Study & Annotate

Highlight important passages, add sticky notes, and draw arrows on PDF textbooks, research papers, and study materials.

💼

Business Documents

Add approval stamps, comments, and annotations to invoices, reports, and contracts during review and approval processes.

🎨

Markup & Review

Draw on design mockups, architectural plans, and presentations to provide visual feedback with shapes and freehand notes.

⚖️ Comparison

KJSynthora PDF Editor vs Alternatives

See how our free browser-based PDF editor compares to popular alternatives.

Feature	KJSynthora	iLovePDF	Smallpdf	Adobe Acrobat
Cost	✓ Free	Free (limited)	Free (limited)	Paid ($24/mo)
No Signup	✓ Yes	✗ Account needed	✗ Account needed	✗ Account needed
Files Stay on Device	✓ 100% Local	✗ Uploaded	✗ Uploaded	Mixed
Add Text to PDF	✓ Yes	Yes	Yes	Yes
Freehand Drawing	✓ Yes	Limited	Paid only	Yes
Digital Signature	✓ Free	Free (limited)	Paid only	Yes
Highlight Tool	✓ Yes	Limited	Paid only	Yes
White Cover Redaction	✓ Yes	✗ No	Paid only	Yes
No Watermark	✓ No watermark	Watermark on free	Watermark on free	No watermark
Unlimited Pages	✓ Yes	Limited free	Limited free	Yes

❓ FAQ

Frequently Asked Questions

Everything you need to know about editing PDFs online.

Is this PDF editor completely free? ▼

Yes. KJSynthora PDF Editor is 100% free with no signup, no watermark, no file limits, and no hidden costs. You can edit and download unlimited PDFs.

Is my PDF file uploaded to a server? ▼

No. All PDF processing happens entirely in your browser using PDF.js and Fabric.js. Your files never leave your device. This makes it safe for confidential documents, contracts, medical records, and sensitive business files.

How do I add text to a PDF? ▼

Type your text in the Content field in the left panel, choose font size and color, then click Add Text. The text box appears on the current page — drag it to position. Double-click the text to edit it inline.

How do I add a digital signature to a PDF? ▼

Click the ✍️ Sign button in the Annotation Tools section. A signature pad appears — draw your signature with your mouse or touchscreen. Click Add to PDF to embed it on the current page. Resize and position as needed, then download.

Can I highlight text in a PDF? ▼

Yes. Click the 🟡 Highlight button in Annotation Tools, then draw a rectangle over the text you want to highlight. Choose from yellow, green, red, or blue highlight colors. The highlight is semi-transparent so the text remains visible.

How do I redact (cover) sensitive information? ▼

Use the White Cover button in the Shapes section. A white rectangle is placed on the page — drag and resize it to cover the sensitive text or information. Download the PDF to permanently hide the covered content.

Does it support multi-page PDFs? ▼

Yes. All pages of a multi-page PDF are loaded and displayed. Use the Prev/Next Page buttons to navigate. You can add text, annotations, and shapes on any page independently. All pages are included when you download the final PDF.

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