# @fastify/helmet vs Source Defense How it works: side-by-side comparison (2026)

[@fastify/helmet](https://cybersectools.com/tools/fastifyhelmet) is a free [runtime application self-protection](https://cybersectools.com/categories/rasp) solution. [Source Defense How it works](https://cybersectools.com/tools/source-defense-how-it-works) is a commercial [runtime application self-protection](https://cybersectools.com/categories/rasp) solution by [Source Defense](https://cybersectools.com/companies/source-defense). Features, integrations, deployment and the company behind each one, side by side.

## Side-by-side comparison

| | @fastify/helmet | Source Defense How it works |
|---|---|---|
| Pricing model | Free | Commercial |
| Category | Runtime Application Self-Protection | Runtime Application Self-Protection |
| Verified | No | No |
| Deployment type | Cloud | Cloud |
| Company size fit | Startup, SMB, Mid-Market, Enterprise | SMB, Mid-Market, Enterprise |
| GitHub stars | 453 | – |
| Last commit | Mar 2026 | – |
| Company | – | Source Defense |
| Headquarters | – | – |

### Use cases and capabilities

| | @fastify/helmet | Source Defense How it works |
|---|---|---|
| Web Security | Yes | Yes |
| Node.js | Yes | – |
| XSS | Yes | – |
| Sandbox | – | Yes |
| Browser Security | – | Yes |

### Core features

**@fastify/helmet**

No features listed.

**Source Defense How it works**

8 features listed. Sign in on the page to see them.

## Which one fits you

Based on what each listing shows: deployment, company size, price and open source.

- [@fastify/helmet](https://cybersectools.com/tools/fastifyhelmet) fits if you are a startup, you need a free product and you want an open-source product.

## @fastify/helmet vs Source Defense How it works FAQ

Common questions when comparing @fastify/helmet vs Source Defense How it works for runtime application self-protection.

### What is the difference between @fastify/helmet and Source Defense How it works?

**@fastify/helmet**: A Fastify plugin that implements HTTP security headers through a wrapper around the helmet library to protect web applications from common vulnerabilities.

**Source Defense How it works**: Client-side security for websites against 3rd party vendor attacks. Built by Source Defense.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes @fastify/helmet and Source Defense How it works?

**@fastify/helmet** is open-source with 453 GitHub stars. **Source Defense How it works** is made by Source Defense. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is @fastify/helmet a good alternative to Source Defense How it works?

Often, yes. @fastify/helmet and Source Defense How it works are both Runtime Application Self-Protection products, and both cover Web Security. Key differences: @fastify/helmet is Free while Source Defense How it works is Commercial, @fastify/helmet is open-source. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [@fastify/helmet vs c/side](https://cybersectools.com/compare/cside-vs-fastifyhelmet)
- [@fastify/helmet vs Source Defense Platform](https://cybersectools.com/compare/fastifyhelmet-vs-source-defense-platform)
- [@fastify/helmet vs Approov Runtime Application Self Protection](https://cybersectools.com/compare/approov-protect-connected-car-apps-vs-fastifyhelmet)
- [Source Defense How it works vs c/side](https://cybersectools.com/compare/source-defense-how-it-works-vs-cside)
- [Source Defense How it works vs Source Defense Platform](https://cybersectools.com/compare/source-defense-how-it-works-vs-source-defense-platform)
- [Source Defense How it works vs Approov Runtime Application Self Protection](https://cybersectools.com/compare/approov-protect-connected-car-apps-vs-source-defense-how-it-works)

## Alternatives to each

- [See all @fastify/helmet alternatives](https://cybersectools.com/alternatives/fastifyhelmet)
- [See all Source Defense How it works alternatives](https://cybersectools.com/alternatives/source-defense-how-it-works)

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Source: https://cybersectools.com/compare/fastifyhelmet-vs-source-defense-how-it-works

For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/fastifyhelmet.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md.

More on @fastify/helmet and Source Defense How it works: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md