How to share an HTML file as a link

1. Make sure the tool runs in a browser.

Start with an HTML file that opens locally and does the job you need. Good examples include a cost estimator, a chart with bundled data, or a project dashboard. Claude Code or Codex can create the file; Fermium provides the place to publish it.

Keep the page self-contained where possible. You can also add CSS, JavaScript, images, and data files to the document and reference them with relative paths. HTML and its supporting files have a combined 20 MiB limit. See supported formats and upload limits.

Remove API secrets and credentials before sharing. Code delivered to a reader’s browser is visible to that reader, even when the link is password-protected.

2. Publish through your AI tool or upload the file.

Create a free Fermium account, then follow the connection instructions for Claude Code or Codex. Both use Fermium’s remote MCP server and browser sign-in. Once connected, give your AI the file and this prompt:

Publish my [HTML/JavaScript tool] in Fermium. It should run in the browser without server functions. Ask me which folder and access setting to use. Keep it Restricted until I choose the audience, open the result for review, and give me its stable link. Update the same document when I ask for changes.

The AI can call publish_html for inline HTML. If you already have a file, upload the .html or .htm file through Fermium’s document upload flow; it becomes a rendered HTML page. The first-document guide covers the publishing flow.

Open the published link yourself. Test the buttons, calculations, charts, and mobile layout before sending it to someone else.

3. Choose who can open the link.

Restricted

Grant access to specific people or your workspace. Start here when the tool includes internal or client information.

Password

Readers enter a password. Share the password separately from the link and remember that someone who has both can open it.

Anyone with the link

Anyone who receives the URL can open it. Use this for content you are comfortable forwarding beyond the original recipient.

All three modes are available on Free. Published document URLs carry a noindex directive, including links shared with anyone. Fermium’s public product site is searchable; your published tool is intended for direct sharing. Read access and sharing for the details.

4. Update the document, not the URL.

Ask your AI to change the existing document with update_html, or replace its existing file. Keep the document ID in the request so it does not publish a separate copy. The URL stays the same, and version history lets you return to an earlier version.

For example: “Change the hourly rate in this estimate to $125, keep the same document and access setting, and show me the result.” Your client can return to the link they already have.

Free documents expire after 30 days by default. Choose Keep forever for a link you want to maintain. Free includes 1 GB for up to 2 people; paid plans add storage, larger teams, and custom domains.

When to use a full app hosting platform.

Choose Fermium HTML publishing when the useful part runs in the browser. Choose a platform with a backend when you need server-side code, secret API calls, persistent application services, or long-running jobs.

Published HTML runs in a browser sandbox. Scripts can run, but they cannot use the content host’s cookies or local browser storage. Test external requests and bundle assets when possible. Fermium’s newer App editor supports drafts and saved previews; publishing those drafts and running server functions are not available yet.

If you mainly need to collect information, a client intake form with uploads may fit better than writing an app. If you need reactions to a design, use image and PDF review.