How to Sign a PDF Online for Free
You can sign a PDF online for free without printing, signing on paper and scanning it again. With PDF Hydra's Sign PDF, you draw, type or upload your signature, place it on the page and download the signed file.
Use it for an offer letter, a rent agreement, a school permission form, an invoice or a visa form. It works on your phone and your computer.
Sign PDF: Draw, type or upload your signature.
Try it freeThree ways to make your signature
Drawing is quick when you are on your phone. Typing is neat but does not look like your handwriting. Uploading a photo of your real signature looks the most natural, and you can use the same image again next time.
- Draw it with your finger on a phone or tablet, or with a mouse on a computer. Go slowly and try a few times until it looks like your usual signature.
- Type your name and use it in a signature style.
- Upload a picture of your signature from paper.
Get a clean signature from paper
If you want your real handwritten signature, sign on white paper with a dark pen. Take a straight, clear photo in good light.
Then open Signature Background Remover. It turns the photo into a clean PNG with a transparent background, so there is no grey or white box around your signature on the PDF.
Save this PNG in a safe place on your phone or computer. Next time a document needs your signature, you can upload it in a few seconds. If an online form asks for a signature image under a set size, such as 20KB, use Resize Image to KB and choose the size the form asks for.
Sign your PDF with PDF Hydra
- Open Sign PDF and upload the PDF you need to sign.
- Draw, type or upload your signature.
- Add the date if needed.
- Place the signature and date in the right spot on the page.
- Download the signed PDF.
Sign PDF: Draw, type or upload your signature.
Try it freeFill the form before you sign
If the PDF has form fields, fill them first with PDF Form Filler, then sign. If you need to fix a typo or change some text, use Edit PDF.
After signing a filled form, you can use Flatten PDF to lock the fields and notes into the page. This keeps your answers from being changed and helps them show the same way in any viewer or upload portal.
Will a signed PDF be accepted
Many offices and companies accept a signed PDF, but rules differ. Some need a wet signature on paper, or a special digital certificate. Check with the office or company that asked for the document before you send it. If they ask for the file by email, send the signed PDF, not a screenshot of it.
Keep a copy of the unsigned original in case you need to sign again.
Your signature stays private
Signing happens in your browser. Your signature and document are not uploaded to any server, and PDF Hydra does not save them. Still, only add your signature to documents you have read and agree with.
Frequently asked questions
How do I sign a PDF on my phone?
Open Sign PDF in your phone browser, add the file and draw your signature with your finger. Place it on the page and download.
Can I use a photo of my signature?
Yes. Upload the image as your signature. For a clean look, first use Signature Background Remover to turn it into a transparent PNG.
Can I add a date with my signature?
Yes. You can add the date and place it next to your signature on the page.
Is my signature saved by PDF Hydra?
No. Signing happens in your browser. Your signature and file are not uploaded to any server.
Related tools
- Signature Background RemoverTurn a photo of your signature into a clean transparent PNG.
- Flatten PDFLock form fields and notes into the page.
- PDF Form FillerType into PDF forms and save them.
- Edit PDFChange the text already in your PDF, even inside tables. Add text, images and shapes.