Sixteen PDF tools, one instruction each.
Every tool here is one thing a proofreader would mark on a page — delete, transpose, close up, substitute — done to a document instead of to a line of type. No account, no sign-up wall, no watermark. Fourteen of them run entirely inside your browser and never upload your file; the two that cannot are in their own group below and say so on their own pages.
Working on a document
| Tool | What it does | Runs in | Same thing, programmatically |
|---|---|---|---|
| Edit a PDF | Change the words already in the PDF, in their original font. | your browser | the document model |
| Annotate a PDF | Highlight, draw and add notes on top of the page. | your browser | the document model |
| Sign a PDF | Draw a signature and place it where it goes. | your browser | the document model |
| Fill in a PDF form | Fill a PDF's real form fields, and flatten them if you like. | your browser | POST /api/v1/forms |
Working with its pages
| Tool | What it does | Runs in | Same thing, programmatically |
|---|---|---|---|
| Merge PDF files | Join several PDFs into one, in the order you choose. | your browser | no endpoint |
| Split a PDF | Pull out the pages you want, or make one file per page. | your browser | GET /api/v1/documents/{id}.pdf |
| Delete pages from a PDF | Remove the pages you do not want to send. | your browser | the document model |
| Reorder PDF pages | Drag pages into the right order. | your browser | the document model |
| Rotate PDF pages | Turn sideways pages the right way up, in the file itself. | your browser | the document model |
Changing what kind of file it is
| Tool | What it does | Runs in | Same thing, programmatically |
|---|---|---|---|
| Convert PDF to Word | Get an editable .docx with the text as text. | your browser | no endpoint |
| Convert Word to PDF | Set a .docx as a PDF that looks the same everywhere. | your browser | no endpoint |
| Convert JPG to PDF | Turn photographs into one document with pages. | your browser | POST /api/v1/pdfs |
| Convert PDF to JPG | Get every page as a JPG or a PNG. | your browser | GET /api/v1/documents/{id}.png |
| Compress a PDF | Get a file under a size limit, choosing what quality to spend. | your browser | no endpoint |
Passwords
These two are the exception, and it is worth saying why rather than burying it. No browser can perform real PDF encryption, so both of these send your file to our server, which encrypts or decrypts it and sends it straight back. The temporary copy is deleted the moment the result is returned and the password is never written down — here is the whole trace.
| Tool | What it does | Runs in | Same thing, programmatically |
|---|---|---|---|
| Password protect a PDF | Put an AES-256 password on a PDF. | our server | POST /api/free/protect |
| Unlock a PDF | Take off a password, or the no-printing and no-copying restrictions. | our server | POST /api/v1/pdfs |
Limits
25 MB a file, three files in one session. Nothing is stored, so closing the tab ends the session — which is also why there is nothing to delete afterwards. An account raises both and keeps the document between sittings.
The one that is not free
Putting a real diagram on a page — boxes, connectors and the whole stencil library, on the PDF itself — needs an account, because it needs somewhere for the document to live between sittings. Draw a diagram on a PDF shows what it does.
Free, but not a page of its own
These live inside the editor rather than on a tool page.
| Place images on a page | Drag a picture in. |
| Rich popups on any word | Select words and attach a note with pictures, tables, code and links. Exported into the PDF as a panel, an appendix entry and a tooltip, so it survives whatever the reader opens it in. |
| Read a scan into editable text | A photographed page becomes words you can select. Runs on our side, so it needs the document to be here. |
What changes
Everything under Free stays free and always will. What an account adds is almost entirely the difference between finishing something in one sitting and coming back to it — plus the three jobs a browser cannot do on its own.
Working on a document
| Diagrams, connectors and stencils | The whiteboard: over 400 stencils, on their own or over a PDF. |
| True redaction | The text is removed from the file, not covered up — which also destroys the versions that still had it. |
| Power OCR: read a barely legible page, and replace the words | Standard reading leaves the page looking like the page: the words go on top, invisible, to select and to search. Power reading is for a page nobody can actually READ — a fax, a photocopy of a photocopy, a map set at six point. It draws the page again from the file at the resolution the file really holds, spends more passes on it, and then replaces the printed words with the ones it read, each on a patch of its own paper colour. Several times the processor of a standard read, which is why it is not in every plan. |
Keeping it
| Keep documents in an account | Without this, a session ends when the tab does. |
| Version history, with who changed what, and a way back | Every revision, who made it, and a way back. |
| Folders | Somewhere to put things. |
| Search inside your documents | Full text, including inside PDFs we have read. |
| High-fidelity export | Rendered on our side rather than by the browser. |
| URL bending | A docubend link that goes on pointing at the current file when the file moves or is replaced. We read what the page declares and obey its robots.txt, carry no credential, and store no bytes — the reader's browser fetches the file from whoever hosts it. |
From your own applications
| An API: make documents from your own software | Client-credentials OAuth: their own software can make a PDF or a diagram, keep it in My documents, and fetch any document back as a PDF, a picture or its own model. |
Keeping the account safe
| Two-factor sign-in | A code from an authenticator app as well as the password. Each person switches it on for themselves — granting it here offers it, it does not impose it, because turning it on FOR somebody is how you lock out the people who did not read the email. |
Working with other people
| Share a document by email | |
| Forms: collect answers on any document | Put fields on any document — a PDF, a scan, a photograph of a paper form — send it to be filled in, and get each submission back as its own document alongside a table of the answers. Whoever fills it in needs no account. |
| Comments | |
| See other people's changes as they happen | Their edits arrive in your window as they save them. |
From your own software
Everything above is something a person does to a file. If what you have is a program — a nightly job with a dashboard to send round, a build that should leave a report behind, a service that describes its own architecture — the API makes the PDF or the diagram and keeps it with your documents. Markdown, HTML, a screenshot, mermaid, SVG or a PDF in; PDF, PNG, SVG or mermaid back out.
Trying it
Fourteen days. Stripe takes a card and does not charge it, and if you cancel before the trial ends no money moves at all. The free tools keep working whatever you decide.