astro-noemail

Build-time and SSR email address obfuscation for Astro

astro-noemail is a tiny Astro integration that protects email addresses from basic scrapers by converting them into HTML entities during build and for on-demand SSR responses.

There is:

• no JavaScript at runtime
• no hydration
• no DOM mutation in the browser
• no adapter dependency

Just safer HTML.

Why this exists

Email addresses published in plain HTML are routinely harvested by simple bots.

Most solutions rely on:

• JavaScript obfuscation
• runtime DOM rewriting
• client-side decoding

These approaches:

• increase page weight
• break with JS disabled
• add unnecessary complexity

astro-noemail solves this during rendering and build output, and produces cache-safe output.

Supported rendering modes

This plugin works across:

• static/prerendered pages
• hybrid sites with both prerendered and on-demand SSR routes
• full SSR sites

For client-only rendering, the plugin can only obfuscate email addresses that appear in the HTML Astro sends from the server. Content created later in the browser by client-side JavaScript is outside its scope.

| Mode | Supported | Notes | | --- | --- | --- | | Static / prerendered | Yes | Obfuscates generated .html files during build | | Hybrid | Yes | Obfuscates prerendered pages and SSR responses | | Full SSR | Yes | Obfuscates HTML responses through Astro middleware | | Client-only rendering | Partial | Only server-rendered HTML is processed; browser-created content is not |

What it does

On astro build, the plugin:

• scans generated .html files in the output directory
• rewrites HTML responses for SSR pages through Astro middleware
• finds plain-text email addresses
• replaces them with numeric HTML entities

Example:

[email protected]

becomes:

info@velohost.co.uk

Browsers render this normally, but basic scrapers do not.

What it does NOT do

This plugin deliberately does not:

• inject JavaScript into the browser
• parse the DOM
• modify Astro source files
• touch files outside the build output
• expose environment variables
• interfere with adapters or rendering

It operates only on HTML responses, not on client-side JavaScript.

Safety guarantees

The obfuscation logic is hardened to:

• skip <script>, <style>, and <noscript> blocks
• avoid double-encoding existing HTML entities
• only mutate files when a change is required
• never crash or fail a build

Astro-specific HTML rewriting is respected.

Installation

npm install astro-noemail

Usage

Add the integration to your Astro config:

import { defineConfig } from "astro/config";
import astroNoEmail from "astro-noemail";

export default defineConfig({
  integrations: [
    astroNoEmail()
  ]
});

That’s it.

No configuration is required.

The public TypeScript types are exported from the main entrypoint, including NoEmailOptions.

Optional configuration

Disable the plugin

astroNoEmail({
  enabled: false
})

This can be useful for local testing or special builds.

Disable SSR rewriting

astroNoEmail({
  ssr: false
})

This keeps the build-time HTML rewrite on, but skips middleware rewriting for on-demand SSR responses.

Mailto links

Email addresses inside visible text and mailto: links are obfuscated.

The links continue to function normally in browsers.

<noscript> behaviour

Astro may rewrite <noscript> content during compilation.

If an email address is moved outside of a <noscript> block by Astro itself, it will be treated as normal HTML text and obfuscated.

This behaviour is intentional and considered safe.

CDN & caching

Because all changes are static:

• output can be cached aggressively
• the plugin works behind any CDN
• Cloudflare, Netlify, Vercel, S3, and similar platforms are fully supported

Failure behaviour

If a file cannot be processed:

• the error is logged
• the build continues
• the site is not broken

The plugin must never block a deployment.

License

MIT License

Copyright (c) 2026 Velohost UK Limited

Author

Built and maintained by Velohost

Website: https://velohost.co.uk/

Project page: https://velohost.co.uk/plugins/astro-noemail/