---
title: "User agent: plain-language definition | Am I Ready for Agents?"
description: "User agent: The name a browser or bot gives itself with each request. What it is, a dated example and where it matters. Dated and sourced."
canonical: https://amireadyforagents.com/glossary/user-agent
site: "Am I Ready for Agents?"
last_updated: 2026-11-04
section: "Glossary"
---

# User agent: plain-language definition | Am I Ready for Agents?

> User agent: The name a browser or bot gives itself with each request. What it is, a dated example and where it matters. Dated and sourced.

Source: https://amireadyforagents.com/glossary/user-agent
Site: Am I Ready for Agents?
Last reviewed: 2026-11-04

# User agent

## In short

The user agent string is how bot rules name a visitor, so your web team needs the exact names of the ones you mean. In the network crawl of 4 Nov 2026, 6.9 percent of sites with a readable robots.txt disallowed ChatGPT-User at the root. Read on in robots.txt and bot rules. The neighbouring terms are robots.txt and Verified bot.

## Definition

The name a browser or bot gives itself with each request. Robots.txt rules and bot settings use these names, such as GPTBot or ChatGPT-User.

## A dated example

-   Read 4 Nov 2026
    
    In the network crawl of 4 Nov 2026, 6.9 percent of sites with a readable robots.txt disallowed ChatGPT-User at the root.
    
    [Scorecard methodology: the crawl of 4 Nov 2026](https://amireadyforagents.com/scorecards/methodology), read 4 Nov 2026
    

## Where it matters

Bot rules use these names, so your web team needs the exact names of the visitors you mean.

-   [robots.txt and bot rules](https://amireadyforagents.com/university/robots-txt-and-bot-rules)

## Related terms

-   [robots.txt](https://amireadyforagents.com/glossary/robots-txt)A public text file at the root of a site that tells automated visitors which parts they may visit.
-   [Verified bot](https://amireadyforagents.com/glossary/verified-bot)A bot whose operator has proven its identity to your CDN or bot vendor, through signatures, published IP ranges or a directory.

## Sources

1.  [Scorecard methodology: the crawl of 4 Nov 2026](https://amireadyforagents.com/scorecards/methodology) (amireadyforagents.com/scorecards/methodology), read 4 Nov 2026.
2.  [Sector scorecards dataset, edition 4 Nov 2026](https://amireadyforagents.com/scorecards) (amireadyforagents.com/scorecards), read 4 Nov 2026.

Last reviewed 4 November 2026

Reviewed 4 November 2026. [2 sources](#sources), each with the day it was read.