The best free PDF tools do the job inside your browser, so the file never leaves your device, and they hand back a clean file with no watermark and no account. Below are 31 of ours that work that way, grouped by task: start with Merge PDF for combining files, Compress PDF for shrinking them, and Redact PDF when something has to disappear for real. Each entry says what the tool does and where it falls short.
Most PDF jobs are small, so the tool shouldn't cost more than the job is worth, in money or privacy. We judge a free PDF tool on four things:
Many popular PDF sites process files on their own servers. Some cap free use, add watermarks or ask you to sign up after a few files. Terms change often, so check any site's current limits before you rely on it. Every tool in the table below runs in the browser, with no watermark and no account.
| Task | ToolAspect tool | What it does | Good to know |
|---|---|---|---|
| Combine files | Merge PDF | Joins several PDFs into one, in the order you drag them | Encrypted files must be unlocked first |
| Split a file | Split PDF | Cuts by custom ranges, every N pages, or one file per page | Pages are copied, not re-rendered |
| Pull out pages | Extract PDF Pages | Type 2,5-7 or 4-end and get one new PDF | Output follows the order you type unless you tick "keep document order" |
| Remove pages | Delete Pages from PDF | Click × on pages and download a rebuilt file | Deleted pages are left out, not hidden. Bookmarks don't carry over |
| Reorder, delete, rotate | Organize PDF | One thumbnail view for all three jobs | Check bookmarks and links in the output |
| Reorder pages | Rearrange PDF Pages | Drag thumbnails into a new order | Bookmarks don't carry over to the rebuilt file |
| Fix sideways pages | Rotate PDF | Turns pages 90, 180 or 270 degrees, and it sticks | Odd and even shortcuts fix duplex scans |
| Trim margins | Crop PDF | Auto-trims whitespace or applies fixed margins | Sets a CropBox. The trimmed content is still in the file |
| Shrink a file | Compress PDF | Lossless clean-up, or re-render pages at 72 to 300 DPI | Re-render mode turns pages into JPEG images |
| PDF to images | PDF to JPG | Exports pages as JPEG or PNG at 72 to 300 DPI | Several pages download as a ZIP |
| Images to PDF | JPG to PDF | Binds photos or scans into one PDF | JPEG bytes go in untouched, so no quality loss |
| Word to PDF | Word to PDF | Converts .docx to Letter, A4 or Legal | .docx only, not old .doc. Close, not pixel-perfect |
| Spreadsheet to PDF | Excel to PDF | XLSX, XLS or CSV, one section per sheet | Prints the cell grid only. Charts and images are skipped |
| HTML to PDF | HTML to PDF | Typesets pasted HTML into a clean PDF | Doesn't fetch URLs. Images need to be embedded as data URIs |
| Markdown to PDF | Markdown to PDF | Headings, tables, code blocks and clickable links | No print dialog, one-click download |
| Get the text out | PDF to Text | Reads the text layer to .txt or Markdown | Scans come out empty. Run OCR first |
| Read scanned pages | OCR PDF | pdf.js renders each page, Tesseract reads it | 300 DPI is the working standard for scans |
| Type on a PDF | PDF Add Text | Click a spot, type, pick size and color | Draws new text on top. Existing text isn't editable |
| Mark up | PDF Annotate | Highlight, strike through, draw and add notes | Saves real PDF annotations you can edit later in Acrobat or Preview |
| Sign | Sign PDF | Draw or type a signature and drag it into place | One page per pass. No audit trail like a signing platform |
| Stamp | Watermark PDF | Diagonal or tiled text stamps, overlay or underlay | Use overlay on scans, or the page image hides the stamp |
| Hide sensitive info | Redact PDF | Draw boxes, export a rebuilt file | Every page becomes an image, so no text stays selectable |
| Lock forms | Flatten PDF | Bakes form fields into the page, or rasterizes for print | One-way. Keep the original |
| Number pages | PDF Page Numbers | 9 positions, "Page 1 of 24", roman numerals | Can skip the first page |
| Add a password | Password Protect PDF | AES-256 encryption with optional restrictions | Print and copy flags rely on the reader honoring them |
| Edit properties | PDF Metadata Editor | View and change title, author, subject, keywords, dates | Edits the Info dictionary, not the XMP block |
| Strip metadata | Document Metadata Remover | Cleans Word, Excel, PowerPoint and PDF files | For PDFs, empties Info and removes XMP. Leaves tracked changes and comments alone |
| Fix a broken file | Repair Corrupt PDF | Rebuilds cross-reference tables with qpdf | Recovers complete pages from truncated files |
| Spot changes | Compare PDFs | Word-level diff, page by page, side by side | Text only. Misses font or image changes |
| Make a certificate | PDF Certificate Maker | A4 or Letter landscape certificate with signers | Can add a QR code for verification |
| Open Word files | DOCX Viewer | Renders .docx in the browser | Fonts may be substituted. No .doc support |
Merge PDF takes a stack of files, lets you drag them into order, and copies every page into one document. Text stays selectable and images keep their resolution because nothing is re-rendered. Our guide on how to merge PDFs covers the edge cases, like signed files.
Going the other way, Split PDF cuts one file into many, while Extract PDF Pages keeps one subset as a single new file. If you'd rather point and click, Delete Pages, Rearrange PDF Pages and Organize PDF all show thumbnails.
One honest catch: the delete and rearrange tools build a brand-new PDF from copies of your pages. Page content comes through intact, but document-level bookmarks don't. Rebuild any clickable outline afterward. Rotate PDF doesn't have that problem, since it only changes each page's stored rotation. Crop PDF sets a visible area, so it's reversible, and that's also why it's no good for hiding anything.
For images, JPG to PDF embeds your JPEGs as they are, so a batch of photos becomes a PDF of about the same size. PDF to JPG goes the other way and zips multi-page exports.
For documents, Word to PDF handles .docx files. Headings, lists, tables and links carry over, but the layout won't match Word exactly. Excel to PDF prints the values in each cell, including the last calculated result of any formula. HTML to PDF and Markdown to PDF suit invoices, notes and READMEs. If you only need to read a Word file, the DOCX Viewer opens it without converting anything.
To get text out, PDF to Text reads the text layer. Scans don't have one, so use OCR PDF for those. See how to OCR a PDF for DPI and accuracy tips.
PDF Add Text stamps new text wherever you click, which covers dates, initials and filling in forms that have no fields. PDF Annotate writes proper highlight, ink and note annotations, so a colleague can still move or delete them later.
Sign PDF lets you draw or type a signature and place it on the page. That's fine for everyday forms. For contracts that need proof of who signed and when, a signing platform's audit trail is the better fit. Our guide to signing a PDF online explains the difference.
The rest are finishing touches: Watermark PDF for DRAFT or CONFIDENTIAL stamps, PDF Page Numbers for reports, and the PDF Certificate Maker for course or award certificates.
This is where the details matter most. A black rectangle drawn over text isn't redaction, because the words are still in the file. Redact PDF rebuilds each page as an image with your boxes burned in, so the covered text is gone for good. The trade-off is that the whole document loses its text layer. Read how to redact a PDF before you send anything sensitive.
Password Protect PDF applies AES-256 encryption. The open password is the strong part. Print and copy restrictions depend on the reader software playing along. If you need to take a password off a file you own, there's a separate remove PDF password page.
For metadata, the PDF Metadata Editor is good for fixing a title or author. To scrub a file before sharing, use the Document Metadata Remover, which clears the XMP block too. Flatten PDF turns filled form fields into ordinary page content so nobody can quietly change them.
When a PDF won't open, Repair Corrupt PDF rebuilds the file's internal index and salvages the complete pages it can find. It fixes structure, not rendering, so a file that opens with blank pages usually needs something else. Compare PDFs shows word-level changes between two versions, which beats reading both side by side. It won't catch font or image changes.
Don't take anyone's word for it, including ours. These checks take a minute.
| Check | How to test | What a good answer looks like |
|---|---|---|
| Works offline | Load the tool page, turn off Wi-Fi, then run the task | The task finishes and the download works |
| No file in network traffic | Open DevTools (F12), go to the Network tab, run the task | No request carries your file. You may see the tool's own code load, but no upload |
| Download source | Right-click the download link and copy its address | It starts with blob:, meaning it was made in your browser |
| No watermark | Open the output and check every page, including the last | Your document and nothing else |
| No account needed | Try a second and third file in a row | No sign-up prompt or daily limit |
| Quality kept | Try to select text in the output | Text still selects after merge, split, rotate or lossless compression |
The offline test is the simplest. Some tools load their processing code only when you first use them, so run the task once while online, then go offline and run it again. If it fails with no connection, the file is probably going to a server.
Browser tools are limited by your device's memory. Everyday documents are fine, but a scan of several hundred pages at high resolution can slow a tab down or crash it. OCR is the biggest example. It runs on your processor, page by page, and a long file takes a while. Desktop OCR software is usually faster on big batches.
Desktop apps also make sense if you edit PDFs daily, need to change existing text in place, or work with accessibility tagging. For the occasional merge, split, sign or compress, a browser tool is quicker and keeps the file on your machine.
They can be, if the processing happens in your browser. A tool that runs locally never sends the file anywhere, so there's nothing on a server to leak or retain. Test it: load the page, switch off Wi-Fi, and run the task. If it still works, the file stayed on your device.
Usually because server processing costs them money, so the free tier is a trial and the watermark nudges you toward a paid plan. Tools that run in your browser don't carry that cost per file, so there's no reason to stamp the output. Check the terms of any site you use, since limits change.
Yes. The ToolAspect PDF merger reads your files into browser memory with the pdf-lib library, combines them in the order you drag them into, and hands back a download. Encrypted files need to be unlocked first. Nothing is sent to a server.
No. A box drawn on top leaves the text underneath in the file, where anyone can copy or extract it. Real redaction removes the content. The ToolAspect redact tool rebuilds each page as an image with your boxes burned in, so the covered text is gone. The trade-off is that the whole file loses its selectable text.
There's no fixed cap, but the file has to fit in your device's memory while it's being processed. A laptop copes with most everyday documents. Very large scans, hundreds of pages at high resolution, or OCR on long files can get slow or run out of memory, and that's when desktop software is the better choice.