About Heron PDF

Heron PDF is a small set of PDF tools that run inside your browser. There is no server holding your documents, no account to create, and no step at which your file travels anywhere.

Why this exists

Most online PDF tools work by uploading your document to a server, processing it there, and deleting it after some interval you cannot verify. For a shopping list that is fine. For a signed contract, a medical letter, an identity document or a client's accounts, it means handing a copy of something sensitive to a stranger's computer and taking the deletion promise on faith.

That trade stopped being necessary. A browser can read a file from disk, do the work in memory and hand the result straight back, which is what every tool on this site does. The honest cost of working this way is that the ceiling is your own machine rather than a data centre, and that some jobs simply cannot be done at all — see the list further down, which is there so you find the limits before you need them rather than after.

What runs, and where

The site is plain HTML, CSS and JavaScript, built around two well-established open-source libraries: pdf-lib for reading and writing PDFs, and pdf.js for drawing pages. Both are served from this site rather than from a third-party content network, so processing a document makes no external request of any kind.

There is no analytics, no telemetry, no session recording, no cookie and no account. One thing is stored on your device: whether you chose the light or dark theme, as a single word in local storage that never leaves it. The privacy page sets all of this out in more detail, including what the hosting layer unavoidably sees.

Who runs it

One independent developer, working on this alongside client work. Not a company, no team, no funding. That is worth stating plainly, because it tells you how to weigh everything else on this page: there is no support desk, no account manager and no roadmap driven by investors.

How it is funded

It costs almost nothing to run, because there is no server doing the work — which is why there is no paid tier for the tools you see and no reason to invent one. Advertising may be enabled on the free pages at some point, and if it is, the privacy page will describe it before it happens rather than after.

Read the source

The site's source is published, along with the build script that generates these pages and the test suite that checks them, at github.com/webweavelk-ai/pdfnest.

That matters for one reason in particular: the claim on every tool page — that your file is never uploaded — is a claim you should be able to check rather than believe. The code that runs the conversions is right there, it is a few thousand lines with no framework and no build step, and there is no server side to take on trust.

A paid server version is planned for the jobs a browser genuinely cannot do: very large documents, batch processing and an API. It would sit alongside these tools, not replace them.

What it deliberately does not do

• Change words that are already on the page. A PDF stores positioned drawing instructions rather than paragraphs, and its fonts usually hold only the characters already in use, so rewriting existing text reliably is a different and much harder problem than adding to it. The editor adds text, signatures, white-out, watermarks and page numbers; it does not rewrite. Edit the document in whatever produced it and export it again.
• Convert PDF to Word or Excel. This needs a full document-layout engine, of the kind that runs on a server, and a browser is the wrong place to attempt it convincingly.
• Unlock password-protected files. A document that needs a password to open cannot be read without it. That is the point of the password.
• Sign with a certificate. A visual signature shows intent. It does not prove the document has not changed since, and it is not the certificate-based kind some portals require.
• Add its own watermark, or charge to remove one. The only watermark in your file is the one you type.
• Redact. A white-out box hides what is underneath; it does not remove it from the file. Anything that has to be genuinely gone should be removed in the application that produced the document.

Contact

There is no email address attached to the site yet, and rather than print one nobody reads, this section points at the channel that does work: the project's issue tracker at github.com/webweavelk-ai/pdfnest/issues.

That page is public — please do not put anything private in it. If you would rather not write your question in public, open an issue saying only that much and a private channel will be opened for it. A proper private address will be added here before the site runs advertising or takes payments, both of which need a working contact route.

Questions

Is Heron PDF really free?

Yes, and there is no paid tier to be pushed towards later for the tools you see — no daily limit, no queue, no file-size upgrade, and no watermark that a subscription removes. There is no server in the middle and therefore no running cost to recover, which is the whole reason it can work this way.

How can I be sure my file is not being uploaded?

Do not take the claim on trust; test it. Open your browser's developer tools, switch to the Network tab, and watch it while you process a document — you will see no request carrying your file. Then try disconnecting from the internet after the page has loaded: the tools keep working, which they could not do if they depended on a server. Both checks take about a minute.

Who is behind it?

One independent developer, working on this alongside client work. It is not a company, there is no team, and there is no funding behind it — which is worth knowing when you weigh the promises made on this site.

How do I get in touch?

Through the project's issue tracker on GitHub, at github.com/webweavelk-ai/pdfnest/issues. There is no email address for the site yet: printing one that nobody reads would be worse than saying so plainly. That page is public, so please do not put anything private in it — say only that you would prefer not to write it in public and a private channel will be opened for it. A proper private address will be added before the site runs advertising or takes payments, both of which require one.

The tools