How to Use Signature

Last updated: September 22, 2026

Signature lets you add a signature, text, and shapes to a PDF in your browser, and fill interactive form fields directly, with no sign-up and no upload to a server. This guide walks through the whole process and covers the problems people run into most often.

Step by step: sign a PDF

1. Upload the PDF. Open the Signature tool and drag a PDF into the upload box, or click it to choose a file from your device (up to 100 MB). The viewer expands to the full width at 188% zoom (48% on small screens) and the toolbar appears.

2. Create your signature. Open the signature pad and draw with your mouse, trackpad, or finger. You can change the pen color before drawing. If you already have a signature image, upload it instead; a transparent PNG works best.

3. Add text if needed. Use the text tool to type a date, name, or note. Pick a font family, set the size, and apply bold, italic, or a color. The text becomes a movable box on the page.

4. Fill interactive fields if the PDF has them. Text fields, checkboxes, dropdowns, and radio buttons in fillable PDFs can be completed directly. Edited values are saved into the download.

5. Position and resize. Drag each signature and text box to the correct spot, such as the signature line. Use the handles to resize, and the page controls to move between pages. When zoomed in, drag the page itself to pan around it.

6. Download. Click the download button, which enables once you place an element or edit a form field. The finished PDF saves to your device with everything embedded, while scripts, actions, and attachments are stripped for safe sharing. Open it once to confirm before sending it on.

The signature pad explained

The signature pad draws smooth strokes. There are more than twenty pen colors to choose from. Undo removes the last stroke, and Clear wipes the whole pad so you can start again. There is no limit on how many times you redraw.

Your saved signatures

Drawn signatures are saved in the browser so you can reuse them on the next document while the tab is open. The saved signature is cleared when you close the tab, and it is never sent to a server. If you switch browsers, draw it again.

Troubleshooting common problems

The PDF does not load. Make sure the file is a PDF and not a renamed image. Files over 100 MB are rejected, so compress oversized scans first. If the preview stays empty, try a different file to confirm the tool is working.

The signature pad does not respond. On a touchscreen, use a finger or a compatible stylus. On a computer, check that the mouse works in the signature pad. Reload the page and try again if needed.

My signature shows a white box. The uploaded image is not transparent. Use a PNG with a transparent background, or remove the white background with an image editor and upload it again.

Text overlaps the document. Drag the text box to a blank area or shrink it with the resize handle. Zoom in for a closer look before you drop it: the editor opens at 188% (48% on small screens), the fit button jumps to 233% (53% on small screens), you can type any value from 25 to 400 into the zoom field, and dragging the page pans it while zoomed.

The download does not start. If the button is greyed out, place a signature or text box first, or edit a form field. Otherwise check your browser's download settings and allow downloads from this site. Update the browser if the button does nothing. After export, a note tells you if scripts, actions, or attachments were removed.

The page is slow with a large file. Close other tabs to free up memory. Very large PDFs take longer to render because all processing happens on your device.

Frequently asked questions

Is Signature really free? Yes. The tool has no cost, no account, no daily limit, and no watermark. There are no paid tiers and no features locked behind a subscription.

Do my PDFs get uploaded anywhere? No. The PDF is processed entirely on your device. The file is never sent to a server. Saved signatures are cached temporarily in session storage on your device only.

Can I add text to a PDF? Yes. Click the Text tool, click on the page where the text should go, and type. The toolbar above the selected text box lets you set the font family, size from 8 pt to 72 pt, bold, italic, and color. Drag the text where you need it.

Can I sign a PDF on my phone? Yes. The layout adapts to small screens and the signature pad accepts touch input. Open the tool in Safari on iOS or Chrome on Android and draw your signature with a finger.

What signature image format should I upload? A PNG with a transparent background is best because it overlays cleanly without a white box. If your image has a white background, remove it with an image editor before uploading.

Does signing change the original PDF? The signature and text are placed on top of the existing content, and edited form values are baked in. The original pages, layout, and quality are preserved; scripts, actions, and attachments are stripped on export for safe sharing.

Is my signature saved? Your drawn signatures are stored in the browser so you can reuse them while the tab is open. They are cleared when the tab closes and are never sent to a server.

What is the maximum file size? Files up to 100 MB are accepted. Very large PDFs may use more memory in your browser, so performance depends on your device.

Can I add more than one signature? Yes. Add several signatures and text boxes to the same page, and place them wherever you need them.