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User-agent checker

Is this user agent an AI bot?

Paste a user-agent string from your server logs. Get back whether it is an AI crawler, a search engine, a scraper, a monitor or a real browser, and for AI crawlers, which product a crawl feeds and how to block it.

Result

AI crawler: PerplexityBot

Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)

Operator
Perplexity
Purpose
AI search indexers
Feeds
Perplexity
Honours robots.txt
Honours robots.txt

Builds Perplexity's search index. Perplexity states it is not used for training foundation models. Allowing it is what makes a site eligible to be cited in Perplexity answers.

PerplexityBot: block, allow and verify

Try an example

Common questions

How does the checker decide whether a user agent is a bot?

Two layers. First a table of named signatures: AI crawlers, search engines, SEO scrapers, monitors, security scanners and HTTP libraries. Then a set of structural checks for automation that does not name itself, such as a WebKit string with no Safari or Chrome token. The structural rules are deliberately conservative so a real browser is never misfiled.

Is the string I paste stored anywhere?

No. It is read from the URL, classified while the page renders and discarded. The result URL itself is shareable, which is the point: you can link a colleague to the exact classification of a log line.

Why does a real browser show no bot match?

Because it is not one. A Chrome, Safari, Firefox or Edge string returns browser, operating system and device class instead. If a browser string does get flagged, the structural rule that caught it is a bug: email the string to [email protected].

Can a bot fake a browser user agent?

Yes, and many do. A user-agent check catches honest crawlers and careless scripts, which is most automated traffic by volume. Determined scrapers need behavioural or network-level detection. That is why this tool reports what the string claims, and the crawler directory explains how to verify a claim against published IP ranges.

AI Bot User-Agent Checker — NumberHill