How to sign a pdf document online for free
- Step 1Open the tool and add your PDF — Drop the PDF onto the PDF Sign tool. It parses locally and reads the page count, which the target-page field uses as its upper bound.
- Step 2Draw your signature on the canvas — Sign on the white pad with your mouse, trackpad, finger, or stylus. The line is a fixed 2.5pt near-black stroke. The status text flips to
Signature capturedonce you lift the pointer. - Step 3Redraw if needed — Not happy with it? Press Clear to wipe the pad and sign again. The pad must contain strokes before you process, or the tool returns
Draw a signature in the canvas before processing. - Step 4Choose the position on the page — Pick one of
top-left,top-right,bottom-left,bottom-right, orcenter. The signature is inset 40pt from the chosen edges;centerplaces it in the geometric middle of the page. - Step 5Set the width and target page — Enter a width in points (default 180; 60–400). Leave the Target page field blank to stamp the last page, or type a 1-based page number to stamp a specific page.
- Step 6Process and download — Press Process. The engine embeds the signature PNG onto the page and returns a new PDF for download. The original file is untouched on disk.
What you control vs. what is fixed
The full set of controls exposed by the PDF Sign client, with their real defaults and ranges. Anything not listed here is not adjustable in this tool.
| Control | Values | Default | Notes |
|---|---|---|---|
| Signature source | Draw on canvas only | — | Mouse, trackpad, touch, or stylus. There is no type-a-name option and no upload-an-image option in this tool |
| Position | top-left, top-right, bottom-left, bottom-right, center | bottom-right | Corners are inset 40pt; center is the page midpoint. No free drag-to-place |
| Width (pt) | 60–400 | 180 | Height scales proportionally to the drawn signature's aspect ratio |
| Target page | 1 … page count (blank = last) | Last page | Stamps exactly one page. There is no all-pages or every-page option |
| Stroke style | Fixed 2.5pt, near-black (#0c0c0d), round caps | — | Pen colour, thickness, and smoothing are not adjustable |
Tier limits for signing a PDF
The PDF Sign tool processes one file at a time. Limits come from the shared PDF tier table (lib/tier-limits.ts).
| Tier | Max file size | Max pages | Files per run |
|---|---|---|---|
| Free | 2 MB | 50 | 1 |
| Pro | 50 MB | 500 | 1 (signing is single-file) |
| Pro Media / higher | 500 MB | 2,000 | 1 (signing is single-file) |
Cookbook
Common signing situations and exactly which controls to set. The signature is always drawn on the canvas first.
Sign the signature line at the bottom of a one-pager
The default behaviour. A short letter or form where the signature block is bottom-right of the last (and only) page.
Draw signature on canvas Position: bottom-right (default) Width (pt): 180 (default) Target page: blank → last page (page 1) Result: signature stamped bottom-right, 40pt in from the right and bottom edges of page 1.
Sign page 3 of a multi-page agreement
The signature block isn't on the last page. Type the 1-based page number into the target-page field.
Draw signature on canvas Position: bottom-left Width (pt): 220 Target page: 3 Result: signature placed bottom-left of page 3 only; pages 1, 2, 4+ are unchanged.
Make the signature fit a wide signature box
Default 180pt looks small inside a long ruled signature line. Widen it; the height grows in proportion automatically.
Width (pt): 180 → signature ~180pt wide Width (pt): 320 → signature ~320pt wide (height scales) Clamped to 60–400pt by the input control.
Centre a signature for a certificate or award
Documents with a signature line dead-centre (certificates, diplomas) use the center anchor.
Position: center Width (pt): 240 Target page: blank → last page Result: signature centred on the page midpoint.
Stamp a signature, then make it permanent
This tool draws the signature into the page content as an image, so it is already part of the page (not a removable annotation). To strip any other interactive form fields or annotations and produce a fully static document, follow with a flatten pass.
Step 1: PDF Sign → stamp signature on last page
Step 2: /pdf-tools/pdf-flatten → flatten form fields
and annotations into static page contentEdge cases and what actually happens
You press Process without drawing anything
RejectedThe tool requires strokes on the canvas. With an empty pad it returns Draw a signature in the canvas before processing. Sign first, then process.
You expected a legally-binding cryptographic signature
By designThis stamps a visible image, not a PKCS#7/CMS digital signature. It carries no certificate and cannot be cryptographically verified. For that, use the PDF Digital Signature tool; to check someone else's signed PDF, use the PDF Signature Verifier.
You want the signature on every page
Not supportedEach run stamps exactly one page. There is no all-pages option. Run the tool once per page, choosing a different target page each time, or use the PDF Watermark tool if you actually want a repeating mark on all pages.
You want to drag the signature to an exact spot
Not supportedPlacement is limited to the five fixed anchors with a 40pt inset. There is no free drag-and-drop. Pick the closest anchor and adjust the width to fit the available box.
The PDF is password-protected
PreservedThe engine loads with encryption ignored, so it can usually read and stamp the page. The downloaded copy is no longer protected by that password. Re-apply protection afterwards with the PDF Password Protect tool if needed.
Your file is over the tier size limit
RejectedFree is capped at 2 MB; Pro at 50 MB. A larger scan can be shrunk first, then signed. The page-count cap (50 free / 500 Pro) also applies even though signing only touches one page.
The drawn signature looks faint or thin on a dense scan
ExpectedThe pen is a fixed 2.5pt near-black stroke and is not adjustable. Drawing larger on the pad, then setting a larger width in points, produces a bolder-looking result because the whole PNG is scaled up.
You typed a target page higher than the document has
Out of rangeThe page field is bounded by the document's page count. Choosing a non-existent page has no valid target; if the engine cannot find the page it reports PDF has no pages. Use a page within range, or leave it blank for the last page.
Frequently asked questions
Is the signed PDF uploaded anywhere?
No. The PDF is parsed and the signature is stamped entirely in your browser tab. Nothing is sent to a server, which is why confidential documents are safe to sign here.
Can I type my name instead of drawing it?
Not in this tool. The signature pad captures hand-drawn strokes only. There is no typed-name or signature-font option.
Can I upload a photo or scan of my signature?
No. There is no image-upload control. You sign on the canvas with your mouse, trackpad, finger, or stylus, and that drawing becomes the signature.
Is this a legally binding signature?
It produces a visible signature mark, which many parties accept for routine documents. It is not a cryptographic digital signature and carries no certificate. For high-stakes agreements, check your jurisdiction's requirements and consider a certificate-based signature via the PDF Digital Signature tool.
Where exactly does the signature land?
At one of five anchors — the four corners or the center — inset 40 points from the page edges (center is the exact midpoint). The size is the width you set in points, with height scaled to keep the drawing's proportions.
Can I sign more than one page at once?
No. Each run signs exactly one page. To sign several pages, run the tool once per page, changing the target-page number each time.
What page does it sign by default?
If you leave the target-page field blank, it signs the last page, which is where most signature blocks appear.
Can I change the pen colour or thickness?
No. The stroke is fixed at 2.5 points and near-black. To appear bolder, draw larger and increase the output width.
Will the recipient be able to delete my signature?
The signature is drawn into the page content as an image, not added as a separate removable annotation, so it is part of the page. If you also want to lock down form fields, follow with the PDF Flatten tool.
What file types can I sign?
PDF files only. To sign an image or a Word document, convert it to PDF first using a sibling tool such as Image to PDF, then sign the resulting PDF.
How big a PDF can I sign?
Up to 2 MB on the free tier (max 50 pages), 50 MB on Pro (max 500 pages), and 500 MB on higher tiers (max 2,000 pages).
How do I verify a signed PDF someone sent me?
If it carries a cryptographic signature, use the PDF Signature Verifier to check it is intact, covers the whole document, and chains to a trusted root. A drawn image stamp like the one this tool produces is not cryptographically verifiable.
Privacy first
All PDF processing runs locally in your browser using PDF-lib and pdf.js. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.