PDF Editor Complete Guide
Everything you need to know about the free, browser-based sourcecodestack PDF Editor — rotate pages, merge documents, add signatures, apply watermarks, lock with a password, and more. No uploads. No account.
Browser-Based PDF Editing
No server. No sign-up. Just open and edit.
📄 Why a Browser PDF Editor?
Most PDF editors ask you to install software, sign up for an account, pay a subscription, or — worst of all — upload your sensitive documents to someone else's server. The sourcecodestack PDF Editor does none of that. It runs entirely in your browser using pdf-lib and pdf.js, two mature WebAssembly-powered libraries that give you professional-grade PDF manipulation without a single byte of your document leaving your device.
✨ What you can do
🔄 Page Operations
The left panel shows thumbnails of every page. These thumbnails are your main workspace for structural edits.
Rotate
- 1.Hover any thumbnail
- 2.Click the ↺ (left) or ↻ (right) button
- 3.Rotation applies instantly — undo with Ctrl/Cmd+Z
Reorder
- 1.Grab the ⠿ handle at the top-left of a thumbnail
- 2.Drag it to the desired position
- 3.An animated ghost shows the new slot
Delete
- 1.Hover the thumbnail and click the trash icon, or
- 2.Tick the checkbox, select more pages, then click 'Delete (N)'
Duplicate
- 1.Hover any thumbnail
- 2.Click the duplicate icon
- 3.A copy appears immediately after the original
Merge PDFs
- 1.Click 'Merge PDF' in the toolbar
- 2.Select a second PDF file
- 3.Its pages are appended to the current document
Insert blank page
- 1.Click 'Insert Blank' in the toolbar
- 2.A blank A4 page is appended after the last page
- 3.Reorder it to the desired position
✂️ Split & Extract Pages
How to extract pages
- 1Tick the checkbox on every page you want to keep.
- 2The toolbar shows 'Extract (N)' where N is your selection count.
- 3Click 'Extract (N)' to download those pages as a brand-new PDF.
- 4The original document remains untouched in the editor.
💡 Tip
To split a 20-page PDF into two halves: extract pages 1–10 first (save that file), then undo all the deletions and extract pages 11–20. Undo history keeps both operations available.
✍️ Annotations — Text, Images & Signatures
All three annotation modes work the same way: activate the mode from the toolbar, then click anywhere on the main page preview to place the content at that exact position.
Add Text
Set font size and color, activate "Add Text", then click the page. A text box opens inline — type and press Enter or click away to stamp it.
Add Image
Click "Add Image" and select a JPEG, PNG, or GIF file. Then click on the page to place it. Scale defaults to 30% of page width — tweak in the options panel.
Signature
Open the signature pad via the toolbar. Draw with your mouse or finger. Click "Apply" then click the page to stamp it. Use "Add Image" for a pre-made signature file.
💧 Watermarks & Page Numbers
Text Watermark
Watermarks are stamped onto every page at once. Options include:
- •Watermark text (e.g., "CONFIDENTIAL", "DRAFT")
- •Color & opacity (0–100%)
- •Font size
- •Position: center (with rotation angle) or any corner
Page Numbers
Use the "Page #s" toolbar button for fine-grained control:
- •Format template:
Page {n} of {total} - •Position (top/bottom × left/center/right)
- •Font size & color
- •Starting page number offset
🗂️ PDF Metadata Editor
PDF files embed metadata that programs — and sometimes people — can read. The Metadata dialog lets you edit or clear four standard fields:
🛡️ Privacy tip
Click Clear all metadata before sharing a PDF externally. This removes author names, creation software, keywords, and any other identifying information embedded in the file — a common privacy best practice before publishing documents.
🔐 Lock & Unlock PDFs
Password protection and decryption are built-in features that run entirely in your browser. No key or password is ever sent to any server.
Lock with a Password
- 1.Click Lock in the toolbar.
- 2.Enter a user password (required to open the PDF) and confirm it.
- 3.Optionally set an owner password (controls permission overrides).
- 4.Choose which actions to allow: Print, Modify, Copy, Annotate.
- 5.Click Lock & Download to save the AES-128 encrypted file.
Note: the lock process rasterizes pages to images to ensure compatibility across all PDF viewers. Text in the locked copy will not be selectable.
Unlock a Protected PDF
- 1.Open the password-protected PDF.
- 2.A password prompt appears automatically — enter the password.
- 3.The document loads normally. An Unlocked badge appears next to the filename.
- 4.Edit as usual, then click Save Unlocked to download a permission-free copy.
"Save Unlocked" downloads the file — it does not modify the original. Your password stays on your device.
↩️ Undo & Redo
Every destructive action — rotation, reorder, delete, merge, annotation, watermark, page numbers, metadata, lock, unlock — is snapshotted into a 30-step undo history. You can freely experiment without fear of losing your work.
💡 History note
History is held in memory for the current session. Refreshing or closing the tab clears it. For complex workflows, download intermediate versions as checkpoints.
🔒 Privacy & Security
No Uploads
Your PDF is read and processed locally by your browser. No bytes travel over the network.
Passwords Stay Local
Lock and unlock passwords are used only in memory and discarded. They are never logged or transmitted.
Free, No Account
No sign-up, no watermark on output, no file-size limit imposed by a server queue. Completely free.
❓ Common Questions
Does my PDF get uploaded anywhere?
No. Every operation runs inside your browser. The network is never used for your file content.
Can I merge two PDFs?
Yes. Open one PDF, click 'Merge PDF', select a second file. Its pages are appended immediately.
Can I lock a PDF with a password?
Yes. Click 'Lock', set a user password, optional owner password, and permissions. Download the AES-128 encrypted file.
Can I remove a password from a PDF?
Yes. Open the locked PDF, enter the password, then click 'Save Unlocked'. A permission-free copy is downloaded.
Does it work on mobile?
Yes. Touch gestures work for signature drawing and dragging thumbnails. The layout adapts to small screens.
Is there a file-size limit?
No server-side limit. Very large PDFs (100+ MB) may slow down your browser because processing happens in-tab.
Ready to edit your PDF?
Drop a file and you're editing in seconds. No account, no installs, no uploads.
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