White paper
- Input
- Luminância 255, limiar 230
- Expected output
- Transparente (opacidade 0%)
Anything at or above the threshold disappears.
Carregando ferramenta… / Loading tool…
sign pdf with signature image transparent background
The Upload image tab does what a photo editor would: it drops the white paper, keeps only the ink and hands you a transparent PNG, ready for the PDF.
Anything at or above the threshold disappears.
Below 170 (230 minus 60) the pixel does not change.
(230 - 200) / 60 = 0.5 of the original opacity.
With no softness the transition is abrupt and the edge gets jagged.
It only reduces, never enlarges; smaller images stay as they are.
No. pdf.js reads the PDF and pdf-lib writes it inside your browser, and the signature image never leaves the device. The signatures you choose to save live in this browser's localStorage, up to 24 images and 6 signers, and can be deleted one by one. Closing the tab discards the open document. Because nothing is uploaded, the tool is also fine for contracts and sensitive documents.
Dark ink on smooth, light paper under even light. Photos with strong shadow, dark grid or ruled paper, and light pen on a dark background do not work well with luminance-based removal.
No. The image is read and processed in the browser. If you choose to save it, the resulting PNG stays only in your browser's local storage and can be deleted at any time.
Yes. Use the Create initials button, which opens the same creator, and upload the initials image. Initials start smaller (10% of the page width) and can be applied to every page at once.
Simple electronic signature. The tool writes an image of your signature onto the PDF. It is not a certificate-based digital signature (ICP-Brasil) and not an advanced gov.br signature.
A signature image on a document is the simplest type: on its own it proves neither who signed nor that the file stayed the same. It may be enough between parties who agree to use it, but it does not replace the qualified signature (ICP-Brasil certificate) or the advanced one when the law, an agency or the contract requires them.
Legal basis (Brazil): Law 14.063/2020, art. 4 (simple, advanced and qualified electronic signatures) and Provisional Measure 2.200-2/2001, art. 10 (ICP-Brasil certificates and other means accepted by the parties). For formal validity, sign in the federal government service (assinador.iti.br, with a silver or gold gov.br account) and verify at validar.iti.gov.br.
gov.br electronic signature · Verify a signed document (ITI)
All processing happens in your browser: the PDF and the signatures are never sent to a server. Saved signatures stay only in this browser and can be deleted at any time.