Digital Stamp Creator
Create digital stamps (hanko) for business documents. Round, square, and oval shapes with transparent PNG output.
What Is a Digital Stamp Creator?
A digital stamp creator is an online tool for making hanko (seal/stamp) images such as personal seals and date stamps. As more documents go digital, there's growing need to stamp PDFs and Word files. Create ready-to-use digital stamps right in your browser.
sakutto.ai's digital stamp creator processes everything in your browser — your name and organization details are never sent to any server. Customize font, color, size, and border freely, then download as a transparent PNG image.
Perfect for internal approval documents, quotes, invoices, and circulation memos. Digitize your daily stamping workflow without needing a physical seal. Free, no sign-up required.
How to Use the Digital Stamp Creator
- Enter the text for your stamp (e.g., your name or initials)
- Choose a layout (1-line, 2-line, or 3-line) and shape (circle, square, or oval)
- Customize the color, font style, size, and border thickness
- Preview your stamp in real time and fine-tune as needed
- Click "Download as PNG" to save it as a transparent image
Features of sakutto's Digital Stamp Creator
- 100% browser-based
- Your name and stamp data are never sent to any server
- Transparent PNG output
- The background is transparent, so the stamp blends naturally into any document
- Real-time preview
- Every change is instantly reflected in the preview
- Extensive customization
- Adjust shape, color, font style, size, border thickness, and opacity
- Three layout styles
- Choose from a simple 1-line stamp, a 2-line stamp, or a 3-line stamp with date
- Date stamp support
- The 3-line layout lets you create a date-stamped approval seal
Use Cases for Digital Stamps
Internal document approvals
Quickly stamp approval forms, reports, and circulated documents in your organization.
Quotes & invoices
Add a professional-looking stamp to quotes and invoices created in Excel or Word.
Stamping PDF documents
Paste the transparent PNG into a PDF editor to digitally stamp any document.
Remote work
Approve documents from home without needing a physical stamp or seal.
Related Tools
Want to add your digital stamp to a PDF? Use the PDF Compression Tool to reduce file size first. For resizing the stamp image, check out the Image Resize Tool.
Why Digital Stamp Creator on sakutto is safe
Many online tools upload your files to external servers for processing. This tool never sends your stamp data to any server — everything is processed entirely in your browser.
* Some AI-powered tools require server-side processing. Tools that send data to a server will always notify you beforehand.
| Comparison | Typical online tools | sakutto |
|---|---|---|
| Where data is sent | Uploaded to external servers | Nowhere — processed in your browser |
| Data leak risk | Risk during transfer and server storage | No risk — no network transfer occurs |
| External traffic | File data travels over the internet | No file data appears in network logs |
| Offline use | Not possible (server required) | Works offline after initial load |
How browser-based processing works
- WebAssembly (WASM): Processes stamp data in your browser at near-native speed. No server communication occurs.
- Web Workers: Runs on a background thread separate from the main thread, so your browser stays responsive during processing.
- After processing, your browser automatically frees the data from memory. No stamp data remains outside your device.
For IT security teams: How to verify
You can verify that sakutto never sends your stamp data externally by checking the Network tab in your browser's DevTools while using the tool. You'll see that no requests involving your stamp data are made. This can also serve as documentation for your IT security team.
Frequently Asked Questions
Are digital stamps legally valid?
Digital stamps are widely used as informal seals on internal documents, quotes, and similar paperwork that does not require legal binding force. For contracts or documents requiring legal validity, we recommend using a qualified electronic signature service.
Is my data sent to a server?
No. All processing happens entirely in your browser. The name you enter and the stamp image you create are never sent to any server.
What format is the download?
The stamp is downloaded as a PNG file with a transparent background. This means it blends seamlessly when placed on documents in Word, Excel, PDF editors, and more.
Can I change the stamp color and size?
Yes. Choose from preset colors like vermillion, crimson, navy, and black, or pick any custom color. The size is adjustable from 80px to 400px.
Can I create a square stamp?
Yes. You can choose from three shapes: circle, square, and oval. Use circles for personal seals, and squares for company or department stamps.
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