---
title: "Anti-bot system"
url: https://proxy.wiki/glossary/anti-bot-system/
type: Glossary Term
author: "proxy.wiki editorial"
published: 2026-08-19
updated: 2026-08-19
site: proxy.wiki
topics: ["Proxy fundamentals"]
license: CC BY 4.0 — quote freely with attribution to https://proxy.wiki/
---

# Anti-bot system

> Software that decides whether a request came from a human, using signals well beyond the IP address.

**An anti-bot system evaluates incoming requests and decides whether to serve, challenge or block them.** It usually runs as a [reverse proxy](/glossary/reverse-proxy/) in front of the application, which is why blocks arrive before the site’s own code executes.

## Signals it combines

- **Network:** the [ASN](/glossary/asn/), whether the range is hosting, its reputation history.

- **Transport:** [TLS fingerprint](/glossary/tls-fingerprinting/), HTTP/2 settings, header order and casing.

- **Behavioural:** request rate, navigation order, timing regularity.

- **Client-side:** JavaScript execution, [browser fingerprint](/glossary/browser-fingerprinting/), input events.

## Why changing IP alone rarely works

The address is one signal among many, and often not the decisive one. A request from a pristine [residential](/glossary/residential-proxy/) address that presents a fingerprint no real browser produces is still identifiable. Consistency across all layers matters more than the quality of any single layer.

## How blocks present

Rarely as an honest error. Expect challenge pages, silent empty results, deliberately slow responses, or a 200 containing nothing useful. Detecting the block is often harder than avoiding it.