How to add your signature to a pdf without software
- Step 1Drop your PDF into the tool — Open the PDF Sign tool and add the PDF. It is read locally; the page count is detected and used to bound the target-page field.
- Step 2Draw the signature — Sign on the white canvas. The captured drawing is a fixed 2.5pt near-black line. The label shows
Signature capturedafter you finish a stroke. - Step 3Clear and retry if it's wrong — Use Clear to reset the pad and sign again. An empty pad cannot be processed — you'll get
Draw a signature in the canvas before processing. - Step 4Choose where it goes — Select a position:
top-left,top-right,bottom-left,bottom-right, orcenter. Corners are inset 40pt; center is the page midpoint. - Step 5Size it and pick the page — Set the width in points (default 180; 60–400). Enter a 1-based target page, or leave it blank to add the signature to the last page.
- Step 6Process and save — Press Process to embed the signature and download the new PDF. Your original file on disk is unchanged.
Signature insertion controls
Everything the tool lets you set when inserting a signature, plus the real defaults. Controls not in this list do not exist in the tool.
| Setting | Options | Default | Effect |
|---|---|---|---|
| How you sign | Draw on canvas | — | Hand-drawn only; no typed text, no uploaded image |
| Position | 4 corners + center | bottom-right | Corners inset 40pt; center is the page midpoint |
| Width | 60–400 pt | 180 pt | Sets the inserted width; height scales to the drawing |
| Target page | 1 … page count, or blank | Last page | One page per run |
How this differs from related signature tools
Pick the right tool for what you actually need to do with a signature.
| Tool | What it does | Use when |
|---|---|---|
| PDF Sign (this tool) | Stamps a drawn signature image onto a page | You want a quick visible signature mark |
| PDF Digital Signature | Certificate-based cryptographic signing/inspection | You need a verifiable digital signature |
| PDF Signature Verifier | Checks a signed PDF is intact and trusted | Someone sent you a signed PDF to verify |
| PDF Flatten | Merges form fields/annotations into the page | You want to lock a filled-and-signed form |
Cookbook
Insert a signature in the most common situations. Draw on the canvas first, then set the controls below.
Add a signature to the bottom of a form
The most common case: stamp the drawn signature bottom-right of the last page using the defaults.
Draw on canvas Position: bottom-right (default) Width: 180 pt (default) Target page: blank → last page Signature inserted 40pt in from the bottom-right corner.
Place initials in a top corner
Draw your initials instead of a full signature and tuck them into a corner at a smaller width.
Draw initials on canvas Position: top-right Width: 80 pt Target page: 1 Small initials in the top-right of page 1.
Insert on a specific interior page
The signature line sits on page 5 of a longer document.
Draw on canvas Position: bottom-left Width: 200 pt Target page: 5 Only page 5 is modified.
Make a small signature larger without redrawing
The inserted size is driven by the width setting, not by how big you drew. Increase the width to scale the same drawing up.
Same canvas drawing, two widths: Width 120 pt → smaller insert Width 360 pt → larger insert (height scales too)
Sign, then lock the document
After inserting the signature, run a flatten pass so any remaining interactive fields become static page content.
1) PDF Sign → insert drawn signature 2) /pdf-tools/pdf-flatten → flatten the rest of the form
Edge cases and what actually happens
Canvas is empty when you process
RejectedYou must draw before processing. An empty pad returns Draw a signature in the canvas before processing.
You wanted to upload a saved signature image
Not supportedThere is no upload control. The signature is whatever you draw on the canvas in this session. If you keep a signature image, you'd need a different image-overlay workflow such as the PDF Stamp tool.
You want the signature reused across many PDFs automatically
Not supportedThe drawing is not saved between sessions, so redraw it each time. The drawing is captured fresh per run; there is no persistent saved-signature store.
You typed a name expecting a script font
Not supportedThere is no typed-signature mode and no signature font. Draw the signature by hand on the canvas instead.
Encrypted PDF
PreservedThe engine ignores encryption when loading, so it can usually still insert the signature. The output is not re-encrypted; protect it again with the PDF Password Protect tool if required.
File exceeds the tier size or page cap
RejectedFree allows 2 MB and 50 pages; Pro allows 50 MB and 500 pages. Compress or split a larger file before signing.
Signature overlaps existing text in a corner
ExpectedAnchors are fixed and inset 40pt. If a corner already has content, choose a different anchor or reduce the width so the inserted image fits the available space.
Document has zero pages or is corrupt
ErrorIf the engine finds no page to stamp, it reports PDF has no pages. Repair the file first with the PDF Repair tool where available, then try again.
Frequently asked questions
Do I really not need any software?
Correct — it runs in your browser. No Acrobat, no DocuSign, no extension, and no account. You draw, stamp, and download.
Is my signature uploaded to a server?
No. Both the PDF and the drawn signature are processed locally in the browser tab and never transmitted.
Can I insert a signature image file I already have?
No — there is no image-upload option. The signature is drawn on the canvas. If you specifically need to overlay a stored image, look at the PDF Stamp tool.
Can I add the same signature to several PDFs at once?
No. This tool processes one file per run and the drawing is not saved between runs, so you redraw for each document.
What's the default size of the inserted signature?
180 points wide, with the height scaled to keep your drawing's proportions. You can set any width from 60 to 400 points.
Which page gets the signature?
Whichever 1-based page number you type into the target-page field, or the last page if you leave it blank.
Can I move the signature anywhere on the page?
Only to one of five anchors — four corners or the center — each inset 40 points from the edges. There is no free positioning.
Is the inserted signature an annotation a recipient can delete?
No — it is drawn into the page content as an image, so it is part of the page itself, not a separate annotation.
Does this make the signature legally enforceable?
It inserts a visible signature mark. That is accepted for many everyday documents, but it is not a certificate-based digital signature. Check your jurisdiction's rules for important agreements.
Can I sign a Word document or an image?
Not directly — convert it to PDF first (for example with Image to PDF), then add the signature to the PDF.
What's the largest file I can use?
2 MB free, 50 MB on Pro, 500 MB on higher tiers, subject to the page caps of 50 / 500 / 2,000 respectively.
How do I lock the form after signing?
Run the signed PDF through the PDF Flatten tool to merge any remaining form fields and annotations into static page content.
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.