pdf

PDF Fill & Sign

Fill PDF form fields, add text, dates, marks, handwritten signatures, initials, or images, and save the completed PDF locally.

View on GitHub

Local processing

About your filesFiles and content selected in this tool are processed in your browser and are not uploaded to a Browser Kitty backend.

Operation demo See the basic workflow in a short video.

About this tool

PDF Fill & Sign is a local browser tool for completing application forms, confirmations, and other PDFs. Fill supported AcroForm fields directly, or place text, dates, ✓ / × / ○ marks, handwritten signatures, initials, stamps, logos, and other images anywhere on the page.

The selected PDF, form values, signatures, images, and edits are processed in the browser. PDF.js and its worker are embedded in the standalone HTML, the runtime CSP uses connect-src 'none', and saving creates a new completed PDF rather than overwriting the source.

Good for

Fill application or submission PDF form fields and save a completed copy
Add names, addresses, dates, or other text where the source PDF has no form field
Place a handwritten signature or initials from a phone, tablet, or desktop
Overlay a scanned stamp, company logo, or other image on a PDF
Complete a PDF locally without uploading it to a cloud signing service
Save a visually flattened submission copy while preserving the original PDF

What it can do

Key capabilities available in this tool.

Fill common AcroForm fields including single-line or multiline text, checkboxes, radio buttons, dropdowns, and choice lists
Add text, dates, and ✓ / × / ○ marks anywhere on the PDF
Draw signatures or initials with a mouse, finger, or pen, or place an image-based signature asset
Place PNG, JPEG, or WebP stamps, photos, logos, and other images over the PDF
Save text/date additions as FreeText annotations and marks or newly drawn signatures as vector Ink annotations where practical
Move, resize, edit, or delete added items with undo/redo for supported form-value changes
Choose whether to visually flatten entered form values and save a new completed PDF without overwriting the source
Embed PDF.js and its worker in the standalone HTML with connect-src 'none' so PDFs, signatures, and images stay local

How to use

Open the tool and choose one PDF from the device. On desktop, you can also drag and drop it onto the start screen.
If the PDF contains supported form fields, fill them directly. Use Tab / Shift+Tab or the previous/next controls to move through fields.
To add content outside form fields, choose Text, Date, ✓, ×, or ○ and place it on the PDF.
For Signature or Initials, draw with a mouse, finger, or pen, or choose an image. Enable Save on this device only when you intentionally want to store the asset locally.
Use Image / Stamp to place a PNG, JPEG, or WebP stamp, photo, logo, or other image.
Select an added item to adjust its position, size, content, font size, or color, and use Undo / Redo when needed.
Choose Save PDF. Keep Flatten entered values enabled for a visually fixed result, or disable it when supported source form fields should remain interactive.
Save the newly generated PDF. The original source file is not overwritten.

Supported

Input: one PDF up to 100 MiB. Password-protected PDFs are not opened in v1.0.0.
PDF forms: common AcroForm single-line/multiline text, checkboxes, radio buttons, dropdowns/choice lists, and read-only display fields. Signature fields are treated as visual placement guidance.
Added content: text, dates, ✓ / × / ○ marks, handwritten signatures, initials, and PNG / JPEG / WebP images.
Editing: move, resize, edit, or delete Browser Kitty-added items; supported form values and added items participate in Undo / Redo.
Saving: generate a new completed PDF without overwriting the source. Flatten entered values writes visual appearances and hides original widgets from viewing/printing.
Signature storage: the selected PDF and editing session are not persisted. Signature/initial assets are stored in IndexedDB only when Save on this device is explicitly enabled.
Mobile: bottom Tools / Pages / Selected / Save actions, one-finger panning, two-finger pinch zoom, and safe-area-aware dialogs.
Runtime networking: PDF.js 6.3.289 and its worker are embedded with connect-src 'none'; selected PDFs and entered content are not uploaded to an app server.

Limitations and notes

Browser Kitty signatures are visual marks placed on the PDF. Certificate-based digital signatures, identity verification, signature requests, audit trails, and contract-management workflows are not supported.
Password-protected PDFs are not opened in v1.0.0.
Existing XFA form fields are not edited, although text, signatures, and other overlays can still be placed over the page.
Required-field warnings are advisory and do not block PDF export.
Text and date additions are saved as FreeText annotations, but the app does not embed a Browser Kitty-supplied Japanese font into those annotations.
Image-based signatures, stamps, photos, and logos remain raster image annotations.
Flatten entered values hides source widgets and writes their visual appearance; it does not structurally remove the underlying AcroForm objects.

Frequently asked questions

Are PDFs or signatures uploaded to a server?

No. The hosted version downloads the app HTML initially, but PDF parsing, form entry, signature/image placement, and PDF generation run in the browser. The runtime CSP uses connect-src 'none'.

Is this a certificate-based digital signature?

No. It places a visual handwritten or image-based signature on the PDF. It does not provide identity verification, certificate signing, or an audit trail.

Can I fill existing PDF form fields directly?

Yes for common AcroForm text, checkbox, radio, dropdown, and choice-list fields. Existing XFA fields are outside the supported editing scope.

Does flattening completely remove the original form objects?

No. It writes the current visual appearance and hides the original widgets from viewing and printing. It does not physically delete the underlying AcroForm field dictionaries.

Can I draw a signature on a phone?

Yes. Draw a signature or initials with a finger or pen. The PDF view also supports one-finger panning and two-finger pinch zoom.

Offline version and source code

The standalone HTML embeds PDF.js and its worker and uses connect-src 'none'. Open the saved file via file:// to fill PDFs, add signatures or images, and generate completed PDFs without external APIs.

View source on GitHub