Sanitize HTML

Overview

You send HTML and we rebuild it from an allowlist, so anything not explicitly permitted disappears: script and style elements, iframes, forms, on-event handlers, and links using a scheme outside ftp, http, https, and mailto. Four ready-made policies run from plain text through to tables and headings, or you can name your own tags and attributes — a list of your own can narrow what survives but never re-admit active markup. Surviving anchors can be given target and rel attributes for you. The cleaned markup comes back as sanitizedHtml, so nothing overwrites what you sent. Accepts file input via file_ref — no need to extract file content first.

Markup you did not write can carry an attack, and an allowlist that only keeps what it recognises is far safer than a blocklist that tries to name every trick.

When to use it

Scope

Non-goals

• Does not render the markup or run anything in it
• Does not fetch images, stylesheets, or any other linked resource
• Does not keep scripts, styles, forms, or inline event handlers
• Does not resolve relative links, which lose their href instead

Properties

Capabilities

Cost & billing

Flat rate per invocation

File handling

File limits

Constraints this skill applies to your input and generated files. The “Limited by” column shows the static source of each cap; none of these can be raised by upgrading your plan.

How we handle your data

Input schema

Output schema

API contract

curl -sS -X POST "$BASE/v1/execute" -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d '{"skillKey":"web.sanitize_html","input":{"html":"<p onclick=\"steal()\">Welcome</p>"}}'

import { Squillify } from "@squillify/sdk";

const sq = new Squillify({ apiKey: process.env.SQUILLIFY_API_KEY });

const { output } = await sq.execute("web.sanitize_html", {"html":"<p onclick=\"steal()\">Welcome<script>alert(1)</script></p>"});

Errors

Other limits

Limitations

• Does not render the markup or run anything in it
• Does not fetch images, stylesheets, or any other linked resource
• Does not keep scripts, styles, forms, or inline event handlers
• Does not resolve relative links, which lose their href instead
• Keeping scripts, forms, or anything else that has to stay active
• Shrinking markup for transfer, which web.minify_html does

How to call

POST /v1/execute (requires authentication)

{
  "skillKey": "web.sanitize_html",
  "input": {
    "html": "<p onclick=\"steal()\">Welcome<script>alert(1)</script></p>"
  }
}

Examples

{
  "html": "<p onclick=\"steal()\">Welcome<script>alert(1)</script></p>"
}

{
  "ok": true,
  "sanitizedHtml": "<p>Welcome</p>",
  "metadata": {
    "policy": "basic_formatting"
  },
  "removed": {
    "elements": 1,
    "attributes": 1,
    "unsafeUrls": 0
  }
}

{
  "policy": "plain_text",
  "html": "<p><b>Welcome</b> aboard</p>"
}

{
  "ok": true,
  "sanitizedHtml": "Welcome aboard",
  "metadata": {
    "policy": "plain_text"
  },
  "removed": {
    "elements": 2,
    "attributes": 0,
    "unsafeUrls": 0
  }
}

Recommended use cases

• Clean HTML from a person, a scraper, or a model before you show it
• Strip scripts and onclick handlers out of rich-text submissions
• Reduce markup to its visible text with the plain_text policy

Avoid for

• Keeping scripts, forms, or anything else that has to stay active
• Shrinking markup for transfer, which web.minify_html does

Related skills

Composable with

Safety & privacy

• Runs without calling any external service.
• Your payloads are never stored permanently.
• Telemetry captures metadata only — never your payload contents.
• We never train models on your payloads.
• No human reviews your payloads.

Tags