How to sign a PDF in your browser
- Choose a PDF file from your device. The original file is read locally, without being sent to CalcWorthy. Password-protected PDFs may require removing the protection with the document owner's permission first.
- Type the name or mark you want to place in the document. You can draw your signature in the signature box with a mouse, finger or stylus. Use Clear to start the drawing again.
- Choose the page number and a position on the page: near the bottom-left, bottom-right, top-left or top-right. The preview displays the signature location when a compatible PDF browser renderer is available.
- Choose a sensible signature width, then press Download signed PDF. The tool inserts a visible image into the page while keeping all other pages. Verify the output before distributing it.
No document or signature is uploaded. The library handling PDF structure is loaded from this website but runs entirely in your browser; the PDF file stays on your own machine. The download is created as a local Blob. Avoid using private-document tools on untrusted shared devices, where browser downloads may remain visible to other users.
Electronic signatures are not digital certificates
This is a visible electronic signature tool: it places a drawing or text mark on a PDF page. It does not create a cryptographic digital signature. In particular, it does not attach a private-key certificate, timestamp from a trusted authority, biometric verification, audit log or tamper-evident signed byte range. Depending on the recipient and local regulations, a visible mark may not be sufficient for legally regulated workflows.
In a signed contract workflow, the recipient may require a certificate-backed PDF signature, identity verification or a platform that records consent and audit evidence. Use the system requested by the recipient rather than assuming a handwritten graphic is enough. This page cannot decide whether an agreement is legally binding and does not authenticate who operated the browser.
Where the signature appears
The signature is drawn directly onto the chosen PDF page using document coordinates. PDF uses points as its layout units: 72 points equal one inch. The width setting is specified in points, so a 144-point signature is two inches wide on the paper, regardless of monitor resolution. The signature preserves its aspect ratio, and the tool limits its position to stay within the printable page area.
For example, on a US Letter page measuring 612 × 792 points, a 144-point-wide signature positioned in the bottom-right leaves a modest margin from the right and bottom edges. For an A4 page, which measures about 595 × 842 points, the same signature is similarly sized. If the page contains preprinted signature lines, choose the corner matching the document; no automatic detection or complex form filling is performed.
Common PDF signing questions
- Does this edit every page? No. It places one visible mark on the selected page and preserves the other pages, although any PDF rewrite can affect existing certified signatures or advanced interactive features.
- What if the file is password-protected? This tool refuses documents the PDF library cannot open correctly; it is not a password-removal service.
- Can I change an official form? The tool adds a signature graphic. It does not automatically populate fields, verify accessibility tags, preserve complex digital signatures or create a certified form.
- Is my handwriting stored? The drawing remains in page memory until you leave; the resulting signed file is saved only when you choose Download.
Need an image of just your signature, without a document? Use the signature generator. To change page order before signing, try the PDF merger or PDF splitter. Always keep an unchanged copy of important originals.
Frequently asked questions
Is this a legally verified digital signature?
No. It adds a visible graphic or text to the PDF. It does not create a digital certificate, timestamp or cryptographic signature.
Do PDF files leave my device?
No. The source PDF and signature are handled by the browser; the output is a local download.
Can I sign a password-protected PDF?
Password-protected or certified PDFs may be rejected or altered by PDF editing. Use the document owner’s approved signing process.
Does signing change other pages?
The tool inserts a mark on one chosen page; it preserves ordinary content on the other pages, but advanced PDF features and pre-existing cryptographic signatures may not survive a rewrite.
Last updated: October 17, 2026