PDF Editor — Edit PDF Pages, Layers and Security
Reorder, delete and rotate pages. Add signatures, watermarks and page numbers. Change passwords and strip metadata. Every edit happens inside your browser — the file never reaches a server.
What "editing a PDF" actually means
PDF was designed to be a final format — a fixed page description meant to look the same everywhere. That is why editing one is not like editing a Word document, and why tools that promise otherwise usually disappoint.
In practice, almost everything people mean by "edit this PDF" falls into three jobs: changing which pages are there and in what order, adding a layer on top such as a signature or a watermark, or changing the document's properties — its password, its metadata, its colour. PDFCore Studio does all three, locally. What it does not do is rewrite the body text of a page, and the section further down explains the honest way around that.
Edit the pages
Change the structure of the document — which pages exist, what order they are in, and which way up.
Organize Pages
Drag pages into a new order, rotate them individually, and delete the ones you do not want.
Merge PDFs
Combine several documents into one, in the order you choose.
Split PDF
Pull out a page range, or break a document into single-page files.
Rotate Pages
Turn scanned or landscape pages 90, 180 or 270 degrees, permanently.
Edit what sits on top
Add a layer to the pages you already have — a signature, a stamp, a mark, a number.
Sign PDF
Draw a signature or place a stamp, and embed it on any page.
Watermark PDF
Stamp DRAFT or CONFIDENTIAL across every page, at the angle and weight you pick.
Page Numbers
Add sequential numbers or "Page X of Y" counters in any of six positions.
Bates Numbering
Fixed-width legal stamps with a matter prefix, for discovery and exhibits.
Fill Forms
Type into a fillable PDF's fields and save the completed document.
Flatten Forms
Bake filled form fields and annotations into the page so they cannot be changed.
Edit the document itself
Change the properties that travel with the file — its security, its hidden data, its size.
Password Protect
Encrypt the document so it cannot be opened without the password.
Unlock PDF
Remove a password you hold, so the file opens without a prompt.
Redact PDF
Cover content and destroy what is under it, rather than hiding it behind a box.
Edit Metadata
Rewrite or wipe the author, title and software fields hidden in the file.
Compress PDF
Bring the file size down so it clears an email or upload limit.
Grayscale PDF
Convert colour pages to monochrome before printing.
If you need to change the words on the page
PDFCore does not rewrite existing body text, and it is worth saying plainly rather than burying it. Text in a PDF is not a paragraph you can click into — it is a set of positioned glyph-drawing instructions, often with the original font subset embedded and the spacing baked in. Editors that claim to edit it are reflowing a guess, which is why the result so often shifts the layout or swaps the typeface.
The dependable route is a round trip, and every step of it runs locally here:
| Step | What you do | Why |
|---|---|---|
| 1 | Convert the PDF to Word | Turns the glyph instructions back into editable paragraphs. |
| 2 | Edit the .docx in Word, Pages or LibreOffice | A real word processor, where text is genuinely text. |
| 3 | Convert it back to PDF | Produces a clean PDF from the edited source, not a patched one. |
The trade-off is real: complex layouts, multi-column pages and heavy tables will not come back identically. For a contract, a letter or a report it works well. For a typeset brochure, edit the original file instead.
Why editing offline changes the calculation
A cloud PDF editor asks you to upload the document before you can touch it. For a signed contract, a medical record or a document under legal hold, that upload is the event that matters — not the edit.
PDFCore Studio runs the whole edit in your browser's memory using WebAssembly and client-side JavaScript. There is no upload step, so there is no retention policy to read, no processing region to check, and nothing to delete afterwards. Close the tab and the document was only ever on your machine. That is also why there is no file size ceiling — the limit is your own RAM, not somebody's request body cap.
Frequently Asked Questions
What a browser-based PDF editor can and cannot do.
Can I edit the text in a PDF with PDFCore?
Not the existing body text. PDFCore edits pages, layers and document properties — reordering, rotating, signing, watermarking, numbering, passwords and metadata. To change the words themselves, convert the PDF to Word, edit it there, and convert it back; all three steps run locally.
Is the PDF editor free?
The core editing tools are free with no account and no watermark. Some engines — signing, Bates numbering, metadata sanitising, flattening, grayscale — are part of Studio Pro, along with higher batch and file-size ceilings.
Do I need to install anything?
No. Everything runs in a normal browser tab. There is also a Chrome extension if you would rather edit without opening the site, and the workspace keeps working with no network connection once loaded.
Is there a file size limit?
No server-imposed one, because nothing is sent to a server. The practical ceiling is the memory your browser can allocate, which on a normal desktop handles documents far larger than typical upload limits allow.
Can I redact a PDF?
Yes. Drawing a black box over text is not redaction — the text stays in the file underneath and can be copied straight out — so the redaction tool rebuilds any page you mark from pixels, which destroys the covered content instead of hiding it. The cost is that redacted pages become images and lose selectable text.
Open the editor
Drop a PDF into the workspace and every tool above is one click away — nothing uploads.