✅ Free · 🔒 Private · 🚫 No sign-up
PDF Studio: the complete guide
Cromagnon PDF Studio is a free online PDF editor that works entirely in your web browser. You can open a PDF and edit its text, highlight and annotate it, sign it, fill in or create forms, merge several PDFs into one, split a PDF into parts, compress it, protect it with a password, redact private information, compare two versions, make a scanned PDF searchable with OCR, and convert PDFs to and from Word, Excel, images and text.
Everything happens on your own device. Your PDF is never uploaded to a server, so contracts, bank statements, medical letters and exam papers stay private. There is no sign-up, no watermark on your files, no daily limit and no paid plan. Open the studio above, drop in a PDF and start working.
This guide explains every tool in PDF Studio, gives short step-by-step tutorials for the most common jobs, lists the keyboard shortcuts, and answers the questions people ask most often about editing PDFs online.
- 100% free
- No sign-up
- No watermark
- Files stay on your device
- OCR in 100+ languages
- Works on phone, tablet and computer
Features
Everything you can do in PDF Studio
Annotate and sign
Highlight, underline and strike through
Mark up text the way you would with a pen. Highlights and sticky notes are saved as real PDF comments, so other PDF readers can list and edit them.
Sticky notes
Leave a comment on any part of a page for a colleague, a teacher or yourself.
Add text
Type anywhere on a page, with a choice of font, size, colour and alignment. Useful for filling in forms that have no form fields.
Shapes, lines and arrows
Draw rectangles, circles, lines and arrows, solid or dashed, to point things out in a document or a plan.
Free drawing
Draw with a pen to circle words, add marks or sketch.
Sign a PDF
Draw your signature with a mouse or finger, or type it, then place and resize it on the page. No account and no e-signature service needed.
Insert an image
Place a logo, stamp, photo or scanned signature on any page.
Watermark
Stamp text such as DRAFT or CONFIDENTIAL across your pages.
Pages
Merge PDFs
Open several PDFs and combine all of them into a single file in the order you choose.
Split a PDF
Cut a PDF into parts with page ranges such as 1-3; 4-6; 9, or pull out the current page on its own.
Reorder, rotate and delete pages
Move pages up or down, rotate sideways scans, and remove pages you don't need.
Extract pages
Save one page, or a set of selected pages, as a new PDF.
Page numbers
Stamp page numbers such as 3 / 12 on every page in one click.
Header and footer
Add the same text, a date or a page number to the top or bottom of every page.
Bates numbering
Add sequential Bates numbers, the numbering used for legal and court documents.
Crop pages
Trim white margins or cut a page down to the part that matters.
N-up and booklet printing
Put two or four pages on one sheet, or arrange pages for printing a folded booklet.
Edit and protect
Edit PDF text
Change words and numbers that are already in the PDF, such as a typo, a date or an amount.
Fill and create PDF forms
Fill in existing form fields, or add your own: text boxes, long text, dates, check boxes, dropdowns and signature fields.
Find and redact
Search for a name, number or word and black it out on every page, or drag black boxes over anything private. Redaction removes the hidden text for good instead of just covering it.
Password-protect a PDF
Encrypt a PDF with a password so only people who know it can open the file.
Unlock a PDF
Open a password-protected PDF (when you know the password) and save a copy without the password.
Remove metadata
Strip the title, author, subject, creator and producer details hidden inside the file before you share it.
Bookmarks
Add or edit the bookmarks (outline) that let readers jump to chapters.
Compare two PDFs
See what changed between two versions of a document, page by page.
Undo and redo
Every change can be undone and redone, and your work is autosaved in your browser so you can reopen it later with your edits.
Convert and optimise
Compress a PDF
Make a large PDF smaller so it fits email limits and upload forms.
PDF to Word
Extract the text of a PDF into a Word document you can edit.
PDF to Excel and CSV
Pull tables and text rows out of a PDF into an Excel workbook (one sheet per page) or a CSV file.
PDF to JPG and PNG
Save the current page as an image, or every page as JPG or PNG files in a ZIP.
Word, Excel and images to PDF
Turn Word, OpenDocument, RTF, web pages, Excel and CSV files, plain text, or a set of photos into a PDF.
OCR: make a scanned PDF searchable
Recognise the text in scanned pages and photos in more than 100 languages, including English, Urdu, Arabic, Hindi, Chinese and Spanish, so you can search, select and copy it.
Scan with your camera
Photograph paper pages with your phone camera and turn them into a clean PDF.
Print the edited PDF straight from your browser.
AI and study (optional)
Summarise or ask a PDF
Get a summary of a long PDF or ask a question such as "What is the deadline?". This uses your own free AI key (for example Google Gemini), set up once in your account; nothing is sent anywhere unless you use it.
Quick document check
A fast look at the document for common problems before you send it.
Study from a PDF
Send a PDF to Study Studio to turn it into flashcards, a quiz and a summary.
Tutorials
Step-by-step how-to guides
How to edit a PDF online for free
- Press Open PDF above, or drag a PDF onto the studio.
- Choose a tool: Add text to type new text, or More tools → Edit text to change existing words.
- Click on the page where you want to make the change and type.
- Press Export (or Ctrl + S) to download the edited PDF.
💡 Tip: Made a mistake? Press Ctrl + Z to undo. Download original always gives you back the untouched file.
How to merge PDF files into one
- Open the first PDF, then open the other PDFs you want to combine; each one appears as a tab.
- Go to the Pages tab and press Merge every open PDF.
- Check the page order and move pages up or down if needed.
- Export the merged PDF.
How to split a PDF
- Open the PDF and go to the Pages tab.
- Type the page ranges you want, for example 1-3; 4-6; 9.
- Press Split. Each range becomes its own PDF.
- To take out a single page, go to it and press Extract current page.
How to compress a PDF to make it smaller
- Open the PDF and go to Convert & optimise.
- Press Compress this PDF.
- Compare the new size with the old one, then download the smaller file.
💡 Tip: Scanned PDFs (photos of pages) shrink the most. A PDF that is mostly text is often already small.
How to sign a PDF without printing it
- Open the PDF and choose the signature tool.
- Draw your signature with your mouse, trackpad or finger, or type your name for a typed signature.
- Drag the signature into place and resize it from the corner.
- Export the signed PDF and send it.
How to fill in a PDF form
- Open the form. If it has form fields, click a field and type.
- If it is a flat form without fields, use Add text and click where each answer goes.
- Tick boxes with a text "X" or a check-box field, and add your signature.
- Export the filled form.
💡 Tip: Want to make a fillable form for others? Use More tools → Form fields to add text boxes, dates, check boxes and dropdowns.
How to make a scanned PDF searchable (OCR)
- Open the scanned PDF.
- Go to Convert & optimise and press Make a scanned PDF searchable.
- Choose the language of the document (more than 100 are available).
- Wait while the text is recognised on your device, then download the searchable PDF.
How to redact a PDF properly
- Open the PDF and go to More tools → Find & redact.
- Search for the words or numbers to hide, or drag black boxes over the areas.
- Press Redact. The text under the boxes is removed, not just covered.
- Export, then also press Remove metadata before sharing if the file came from someone else.
💡 Tip: Drawing a black rectangle with a normal shape tool does not remove the text underneath. Always use Find & redact for private information.
How to convert a PDF to Word, Excel or JPG
- Open the PDF and go to Convert & optimise.
- Choose PDF to Word for editable text, PDF to Excel for tables, or the JPG and PNG buttons for images.
- Download the converted file.
How to password-protect a PDF
- Open the PDF and choose Password protection.
- Type a password (at least 4 characters) twice.
- Press Download protected PDF. Anyone opening it will need the password.
💡 Tip: Keep the password somewhere safe. Nobody, including Cromagnon, can recover it for you.
Work faster
PDF Studio keyboard shortcuts
Shortcuts don't fire while you are typing in a text box, except Ctrl + S. On a Mac, use ⌘ instead of Ctrl.
Privacy
Private by design: your files stay on your device
Most online PDF tools upload your file to their servers, process it there and keep it for a while. PDF Studio works differently: the PDF is opened, edited, converted and saved inside your browser on your own device. The file is never uploaded to Cromagnon.
This also means PDF Studio keeps working on a slow connection, and large files don't have to travel over the internet twice. Recently opened PDFs are kept only in your own browser storage so you can reopen them with your edits; clear them at any time.
The optional AI summary is the only feature that sends text anywhere, and only to the AI provider whose key you added yourself, only when you press the button.
Comparison
PDF Studio compared with typical online tools
| Cromagnon PDF Studio | Typical online PDF tools | |
|---|---|---|
| Price | ✅ Free, every feature | Free with limits, then a monthly plan |
| Sign-up | ✅ Not needed | Often required |
| Watermark on files | ✅ Never | Sometimes on free files |
| Daily task or file-size limits | ✅ None (limited only by your device) | Common |
| Where your PDF is processed | ✅ On your device | Uploaded to their servers |
| OCR languages | ✅ 100+ | Varies, often fewer on free plans |
| Edit, sign, merge, split, compress, redact, compare | ✅ All in one workspace | Usually separate tools |
Made for everyone
Who uses PDF Studio?
Students
Annotate lecture notes, merge assignment files, compress a PDF for an upload portal, and turn readings into flashcards.
Teachers
Mark up homework, add page numbers to worksheets, and make fillable PDF forms for class.
Office workers
Sign contracts, fill forms, merge reports and convert PDF tables to Excel.
Freelancers and small businesses
Sign agreements, add a watermark or logo, and send smaller invoice PDFs.
Lawyers and paralegals
Redact privileged information, add Bates numbers, and compare two versions of an agreement.
Anyone with paperwork
Scan a document with a phone camera, fill in a government form, or password-protect a bank statement.
Troubleshooting
Common problems and how to fix them
My PDF is password-protected
Open it and type the password when asked. To remove the password for good, save an unlocked copy. PDF Studio cannot open a PDF if you don't know the password.
I can't select or search the text
The PDF is probably a scan (a picture of a page). Use Make a scanned PDF searchable to run OCR first.
The file is too big to email
Use Compress this PDF. For scanned documents, scanning at a lower quality also helps.
The edited text looks slightly different
PDFs often use fonts that are embedded only partly. PDF Studio uses the closest available font; choosing a standard font such as Arial gives the most even result.
Some pages are sideways
Go to the page and press Rotate page clockwise until it is upright, then export.
The studio is slow on a very large PDF
Everything runs on your device, so very large files depend on your computer or phone. Close other tabs, or split the PDF into parts and work on each part.
FAQ
Frequently asked questions
Is PDF Studio really free?
Yes. Every feature is free with no sign-up, no watermark and no daily limit. There is no paid plan for PDF Studio.
Are my PDF files uploaded to a server?
No. Your PDF is opened and edited inside your browser on your own device. It is never uploaded to Cromagnon.
Can I edit the existing text in a PDF?
Yes. Use More tools → Edit text to change words and numbers that are already in the PDF, or Add text to type new text anywhere.
How do I merge PDF files for free?
Open all the PDFs you want to combine, go to the Pages tab and press Merge every open PDF, then export the single merged file.
How do I split a PDF into separate files?
Go to the Pages tab, type page ranges such as 1-3; 4-6, and press Split. Each range becomes its own PDF.
How can I reduce the size of a PDF?
Open the PDF, go to Convert & optimise and press Compress this PDF. Scanned PDFs usually shrink the most.
Can I sign a PDF online without printing it?
Yes. Draw or type your signature, place it on the page, and export the signed PDF. No account is needed.
Is a signature made in PDF Studio legally valid?
A drawn or typed electronic signature is accepted for many everyday documents in many countries, but rules differ by country and document type. For legal or official documents, check what the receiver requires.
Can I fill in a PDF form?
Yes. Click into existing form fields and type, or use Add text on a flat form. You can also create your own fillable fields.
Does PDF Studio do OCR?
Yes. Make a scanned PDF searchable recognises text in more than 100 languages, on your device.
Can I convert a PDF to Word or Excel?
Yes. PDF to Word extracts the text into an editable document, and PDF to Excel puts tables and text rows into a workbook. Complex layouts and images are not converted to Word.
Can I convert Word, Excel or images to PDF?
Yes. Use the convert buttons to turn Word, OpenDocument, RTF, web pages, Excel, CSV, text files or images into a PDF.
How do I remove a password from a PDF?
Open the PDF with its password, then save an unlocked copy. You must know the password; PDF Studio does not crack passwords.
Is redaction permanent?
Yes. Find & redact removes the text under the black boxes from the file, not just hides it. Remember that a normal black shape does not remove text.
Does it work on a phone or tablet?
Yes. PDF Studio works in modern browsers on Android, iPhone, iPad, Windows, Mac, Linux and Chromebook. You can even scan pages with your phone camera.
Do I need to install anything?
No. It runs in your web browser. There is nothing to download or install.
Is there a file-size limit?
There is no fixed limit. Because everything runs on your device, very large PDFs depend on your device's memory.
Will my edits be lost if I close the tab?
Your work is autosaved in your browser. Reopen the studio and pick the file from Recently opened to continue with your edits.
Can other PDF readers see my highlights and notes?
Yes. Highlights and sticky notes are saved as standard PDF comments that readers such as Adobe Acrobat can list and edit. Text, shapes and signatures are drawn into the page.
What are the keyboard shortcuts?
Ctrl + Z undo, Ctrl + Y redo, Ctrl + S export, + and - to zoom, 0 to reset zoom, Delete to remove the selected annotation and Esc to deselect it. On a Mac use ⌘ instead of Ctrl.
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