Sign PDF — Add Your Signature Online
Draw, type, or upload a signature onto your PDF.
Drop your PDF file hereTap to select a file
Supports PDF, up to 200MB
What to do next
Related tools
About Sign PDF
Sign PDF runs the PDF document workflow job locally inside your browser. Draw, type, or upload a signature onto your PDF. The work happens on your machine, the result is generated on your machine, and the page exposes the controls you need to drive it without burying them in menus.
Internally the tool runs on the open-source pdf-lib JavaScript library — the same processing stack used by professional desktop pipelines, just compiled for the browser. PDF files are accepted natively. 200 MB is the practical ceiling, set so the tool stays responsive on phones and older laptops.
Most people land on Sign PDF via a search at the moment they actually need the tool. That shapes the design: the page is a single screen with the input on one side, the controls in the middle, and the result on the other, so a first-time visitor can complete the job without reading documentation.
The browser sandbox isolates the page's JavaScript from the rest of the system, the same way it isolates every other tab you have open. Sign PDF works inside that sandbox: it reads the file you give it, processes it with the open-source pdf-lib JavaScript library, and writes the result back. Nothing leaves the page's memory unless you choose to download or copy it.
A practical note on limits: Sign PDF accepts inputs up to 200 MB per run, and the tool processes one input at a time to keep memory usage predictable. If you ever bump into the ceiling, the cause is the size of the input.
Sign PDF sits in a small group of related tools. Useful neighbours include Protect PDF, Watermark PDF, Compress PDF, and Merge PDF. They are designed to compose: the output of one is a sensible input to the next, so a multi-step task is usually a sequence of single-click operations.
Sign PDF sees the most use from teachers distributing course handouts and legal teams preparing exhibit bundles, but the design is intentionally generic enough that you do not need a specialist background to get a good result. The defaults aim at the most common case so a first-time user can get the right output without changing any settings.
When the job finishes, Sign PDF hands you the result as `{name}-signed.pdf`. Filenames are derived from your input where possible, so a quick batch of jobs leaves you with a tidy folder rather than a pile of generic "output (3)" files. Nothing is auto-saved on Favtoo's side because nothing was ever sent there.
Sign PDF keeps the control set focused. Every option on the page is there because a real workflow needs it, and the defaults aim at the most common case so a first-time user can get the right output without changing any settings.
Sign PDF is one example of a broader pattern: utility software increasingly works as single-page, client-side experiences. Every page in the catalog is shaped that way, which keeps each tool fast to load and easy to recommend in a single link.
Tips from users who reach for Sign PDF regularly: process one input first to confirm the settings produce what you expect before committing to a batch; treat the page as the working surface and avoid leaving large jobs running in a backgrounded tab where the browser may throttle JavaScript; and if a particular file fails, check whether the source is intact by opening it in its native viewer — most "tool errors" are actually input errors.
Sign PDF fits the gap where opening a desktop app feels heavy and writing a script feels overkill. The page handles the common PDF document workflow task with sensible defaults so a single visit usually completes the job; for highly specialised work, a dedicated desktop application can offer more knobs to turn.
If Sign PDF appears to hang, the engine is almost certainly still working — large inputs simply take longer to process inside a browser than they would on a server with multi-core scheduling. For inputs near the 200 MB cap, give it up to a minute on a typical laptop before assuming something is stuck.
That is the whole tool. Use Sign PDF for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.
How it works
- 1Open Sign PDF in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
- 2Drop a PDF file onto the upload area, or click to pick one from your device.
- 3Tweak the controls if the defaults are not quite right for your input. The options are kept short and labelled in plain language.
- 4Click to start the job. The engine (the open-source pdf-lib JavaScript library) processes the input in the page; you can watch the progress indicator until it completes.
- 5Download the result as `{name}-signed.pdf`. The file is generated in your browser and saved through your normal download flow.
- 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.
Common use cases
- Compress a marketing deck so the email send-out finishes in seconds using Sign PDF.
- Split a 200-page exhibit bundle into one PDF per exhibit.
- Shrink a scanned lease so it fits past an email gateway.
- Reorder pages of a multi-chapter scan into the correct reading order.
- Add page numbers to a draft report before circulating it for review.
- Strip blank or test pages from a scanned document.
- Extract a specific signed page from a long contract bundle.
- Convert a bundle of invoices into a single archival PDF.
FAQ
How can I create my signature?
Draw with your mouse or finger, type your name to generate a signature, or upload an image of your signature.
Is this a legally binding signature?
This adds a visual signature image. For legally binding digital signatures with certificates, use dedicated e-signature software.
Can I place the signature anywhere?
Yes — click anywhere on the page to position your signature, then resize as needed.
How long does Favtoo retain my data after using Sign PDF?
Favtoo keeps no copy of your file because Favtoo never receives your file. Sign PDF runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.
What does Sign PDF do that command-line tools do not?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. Sign PDF sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common PDF document workflow operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
What input formats are supported by Sign PDF?
Sign PDF accepts PDF. If your input is in a format that is not directly supported, convert it first using one of Favtoo's converter tools — every Favtoo converter outputs a file that is a clean input to the next tool in the chain.
How do I know I am using the latest version of Sign PDF?
Sign PDF is updated whenever the underlying engine releases an improvement or a bug fix. Because the tool is delivered as a static page, every visit fetches the latest version automatically — there is no "version" to manage on your end. If a particular release ever changes default behaviour, the change is documented on Favtoo's changelog so you can confirm what shifted.
How accessible is the Sign PDF interface?
Sign PDF uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
Is the source for Sign PDF available?
Sign PDF is a static page running an open-source engine in your browser, so a typical corporate firewall does not get in the way as long as it allows JavaScript to load from Favtoo. For teams that need to host it themselves on an internal network, the underlying engine (the open-source pdf-lib JavaScript library) is open-source and can be packaged into a private build with the same behaviour. Reach out via the Contact page if that is something you are exploring.
Is it safe to use Sign PDF on confidential files?
Your file is processed inside your browser by the open-source pdf-lib JavaScript library. The engine reads the file's bytes from your tab's memory, computes the result, and writes the result back into the tab. You can confirm what the page does by opening developer tools and watching the Network tab during a run — the requests you see are for the tool's static assets only.
Why is my browser prompting me when I open Sign PDF?
Sign PDF only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.
Which browsers are supported by Sign PDF?
Sign PDF works in any modern browser released in the last few years — Chrome, Edge, Firefox, Safari, Brave, Arc and the major Chromium derivatives are all supported. The underlying engine relies on widely-supported web APIs, so there is nothing exotic to install. If you are on a very old browser version and the tool fails to load, updating to the latest release of your preferred browser is the only fix needed.