How FormVu Adds Signature Fields to Converted HTML Forms

TL;DR

FormVu’s May 2026 update introduces a native HTML signing interface that allows users to draw, type, or upload signatures directly within converted web forms. By enabling a single JVM flag, these visual signatures are seamlessly embedded back into the PDF without requiring complex cryptographic infrastructure.

Digital Signatures: PDF vs HTML

If you convert PDF forms to HTML, you’ve probably run into the signature problem. Every other HTML form signature field converts cleanly, text inputs, checkboxes, dropdowns, radio buttons all have direct HTML equivalents whereas signature fields don’t. The PDF spec ties them to cryptographic infrastructure (certificate chains, byte ranges, PKCS#7 envelopes) that doesn’t exist in a browser.

Implementing a digital signature in HTML has always meant bolting something on after the fact. Users don’t need to download the raw PDF, sign it, and upload it back.

FormVu’s May 2026 release adds a digital signature field to the HTML output. Signature fields in the source PDF now convert to a browser-based signing interface, just like every other form field.

How the HTML signature field works

When FormVu encounters a signature field in a source PDF and signing is enabled, the converted HTML includes an HTML electronic signature input at the same position in the form. The interface gives users three ways to sign:

• Draw a signature directly in the browser
• Upload an image of their signature
• Type their name as text

No additional JavaScript libraries, no manual integration per form.

Enabling the signature field in HTML output

No need to write electronic signature HTML code yourself. The feature is controlled by a single JVM flag:

-Dorg.jpedal.pdf2html.useFormVuSigning=true

Or via the Java API:

FormViewerOptions options = new FormViewerOptions();

options.setUseFormVuSigning(true);

Set it to true and signature fields in the source PDF will convert to the signing interface. Set it to false (or omit it) and you get the previous behavior, signature fields render as empty space.

You can find the Javadoc for FormVu digital signing here.

What this is (and what it isn’t)

FormVu’s signature feature is visual image-based signing, not cryptographic signing. The user draws, uploads, or types a signature, and that image is placed on the signature field. There’s no certificate embedding, no hash validation, no PKCS#7 envelope generated in the browser.

This approach works better for converter HTML forms since you’re outside the PDF signing infrastructure when signing. The browser captures the signature input, storing it, embedding it back into a PDF.

If you need cryptographic signatures applied to the original PDF document, use JPedal directly.

Why this matters for PDF-to-HTML conversion

Signature fields were a major form field type that FormVu couldn’t convert before. For teams in insurance, government, healthcare, or compliance, where forms almost always require a signature, this was the gap that kept them serving raw PDFs or maintaining custom workarounds for every converted form.

That constraint is gone. With useFormVuSigning enabled, every signature field in the HTML form works. One flag, no per-form integration work.

Version and compatibility

Available in the May 2026 release of FormVu. There are no changes needed to your existing conversion pipeline beyond setting the JVM flag. The generated signature interface works in all current browsers.

FormVu allows you to