Signerra
100% Free · Client-Side · Private

Add Images to PDF Instantly

Insert signatures, stamps, logos or any image directly into your PDF. Drag, resize and position freely. Everything stays on your device — zero uploads.

How to Add an Image to a PDF

1

Upload your PDF

Drag and drop or click to select the PDF you want to edit. It opens instantly in your browser without any server upload.

2

Choose & place your image

Click "Upload Image" and select a PNG, JPEG or WebP file. Then click anywhere on the PDF page to place it. Drag to reposition; drag the resize handle to scale.

3

Download your PDF

When everything looks right, click "Download PDF". The file is created locally on your device in seconds.

Common Use Cases

✍️

Signature Images

Place a scanned or photographed wet signature on contracts, letters and forms without printing.

🏢

Company Stamps & Logos

Add your company stamp or logo watermark to invoices, proposals and official documents.

🖼️

Photos & Diagrams

Embed photos, charts or diagrams directly into PDF reports or presentations.

⚖️

Notary Seals

Insert a notary or certification seal image onto legal documents quickly and accurately.

Why Signerra is 100% Private

No Server Uploads

Unlike most PDF editors, your files never leave your device. All processing happens locally in your browser using WebAssembly (pdf-lib).

Instant Results

Because there is no round-trip to a server, images are embedded and the PDF is ready to download in milliseconds.

Always Free

No accounts, no watermarks, no usage limits. Signerra is free for everyone, forever.

M

My take on PDF Privacy

"Uploading sensitive documents like legal contracts or non-disclosure agreements just to paste a signature image is a massive privacy risk. Server-side tools process your signature and document data on unknown infrastructure. Signerra was built to solve this by bringing the editor directly to your browser. Utilizing WebAssembly, your files stay strictly on your device. Zero server uploads mean zero chance of a data breach."

Expert Insights

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What is the primary security advantage of adding images to a PDF client-side?

Absolute data isolation. When you add a signature or a company stamp to a contract, uploading it to a third-party server exposes highly sensitive PII. Client-side processing happens inside your browser's local memory. The raw file data never traverses the internet, ensuring full compliance with data privacy laws.

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How does Signerra handle embedding images without a backend server?

We use WebAssembly via the pdf-lib library to manipulate the PDF binary structure directly in the browser memory. We read your uploaded PNG or JPEG as an ArrayBuffer, convert it to an embedded PDF image object, calculate the exact visual coordinates based on your drag-and-drop actions, and generate the final PDF file natively on your CPU.

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Why might placing a high-resolution image in a large PDF perform differently depending on the device?

Client-side tools depend entirely on your local hardware. Embedding a massive 4K image into a 100-page PDF requires the browser to allocate significant RAM to handle the file buffers. Modern devices handle this in milliseconds, but older mobile devices with limited memory might struggle to allocate enough space for large buffers.

Frequently Asked Questions

Can I add a signature image to a PDF?

Yes. Upload your signature as a PNG or JPEG, click to place it on the correct page, drag it to the right position, resize it to your liking, and download the finished PDF.

What image formats are supported?

You can upload PNG, JPEG, JPG, WebP, and GIF images. For best quality and transparent backgrounds, PNG is recommended.

Is my PDF or image uploaded to a server?

No. Everything runs locally in your browser using WebAssembly (pdf-lib). Your files are never sent to any server.

Can I add multiple images to the same PDF?

Yes. Upload and place as many images as you need across any page of your PDF before downloading.

Can I resize the image after placing it?

Yes. After placing an image, hover over it to reveal the resize handle in the bottom-right corner. Drag it to scale the image while keeping its aspect ratio.

Useful sources