---
title: Block bad user-agents
summary: Check for known bad bots and crawlers and deny traffic.
url: https://www.fastly.com/documentation/solutions/examples/block-bad-user-agents
---

Check for known bad bots and crawlers and deny traffic.

## VCL

[Try it in Fastly Fiddle](https://fiddle.fastly.dev/d09e3a8b)

## Compute

### Rust

[Try it in Fastly Fiddle](https://fiddle.fastly.dev/199ba6dc)

### Javascript

[Try it in Fastly Fiddle](https://fiddle.fastly.dev/c0d22573)

### Go

[Try it in Fastly Fiddle](https://fiddle.fastly.dev/bf506b95)