What is Outbrain?

Outbrain is a bot in the advertising and marketing bots category, operated by Outbrain.

Bot name
Outbrain
Operator
Outbrain
Type
Bot
Respects robots.txt
Not confirmed
robots.txt user agent
outbrain
Signs requests (Web Bot Auth)
No

About Outbrain

The Outbrain crawler analyzes content on publisher websites for the purpose of serving ads.

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

Outbrain user agent

Outbrain identifies itself with this user agent string:

  • Mozilla/5.0 (Java) outbrain

Anyone can copy a user agent string. Transfon Security also checks where each request comes from, so a request that claims to be a known crawler but comes from the wrong network is treated as a fake, not as the real crawler.

How to block Outbrain in robots.txt

We have not confirmed whether Outbrain follows robots.txt. Add a rule, then check your logs to see that it stopped. robots.txt is a plain text file at the root of your domain, such as https://example.com/robots.txt.

Block Outbrain from the whole site

User-agent: outbrain
Disallow: /

Block Outbrain from some folders

User-agent: outbrain
Disallow: /private/
Disallow: /search

Allow Outbrain only on some folders

User-agent: outbrain
Allow: /blog/
Disallow: /

Allow Outbrain and block other crawlers

User-agent: outbrain
Allow: /

User-agent: *
Disallow: /

Things to know

  • Each host needs its own file. Rules on www.example.com do not apply to shop.example.com.
  • A crawler obeys only the most specific group that names it. Once you add a User-agent: outbrain group, Outbrain ignores your User-agent: * rules, so repeat any that should still apply.
  • The user agent name is not case sensitive. We take outbrain from Outbrain's user agent; check Outbrain's own documentation if it publishes a different robots.txt name.
  • Crawlers cache robots.txt, so changes can take up to a day to apply. Disallow stops crawling but does not remove pages already collected or indexed.

Limits of robots.txt

  1. Outbrain may not follow the rule. robots.txt is a request that nothing enforces, and we have not confirmed that Outbrain follows it. Check your logs after adding a rule.
  2. The user agent could be fake. robots.txt matches the name a request claims. Anyone can send Outbrain's user agent, and a scraper using it is not bound by Outbrain's robots.txt policy. Only checking the source network tells a real Outbrain from a fake one.

Treat robots.txt as a statement of your policy, and enforce it where requests arrive.

Who should care about Outbrain

Publishers

Ad verification and contextual crawlers like Outbrain can decide whether your pages get demand. Blocking the ones your partners use can lower fill rates.

Transfon Security for publishers

Media buyers and advertisers

Outbrain checks pages for ad platforms. Its visits to landing pages are not users, so exclude them from conversion data.

Transfon Security for advertisers

E-commerce

Ad platforms send crawlers like Outbrain to check product landing pages. Keep it allowed so ads are not disapproved, and out of analytics.

Transfon Security for e-commerce

SaaS and APIs

Allow Outbrain on landing pages linked from your ads, and keep it off the app.

Transfon Security for SaaS and APIs

Block Outbrain with Transfon Security

robots.txt is a request, not an enforcement. Transfon Security shows Outbrain by name in the Top Bots report, so you can see how often it visits and which pages it reads. Block or allow it with a User Agent rule, or slow it down with a rate limit decision rule.

Transfon Security

Control Outbrain on your site

  • See every Outbrain visit and the pages it reads
  • Spot bots that fake trusted crawler names
  • Block, allow or rate limit Outbrain with one rule
  • Works with or without robots.txt support

Frequently asked questions

What is Outbrain?

Outbrain is a bot in the advertising and marketing bots category, operated by Outbrain. The Outbrain crawler analyzes content on publisher websites for the purpose of serving ads.

Does Outbrain respect robots.txt?

We have not confirmed whether Outbrain follows robots.txt. Add a robots.txt rule, then check your logs to see that it stopped, and block it by user agent if it did not.

How do I block Outbrain?

Add "User-agent: outbrain" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "outbrain" at your WAF. In Transfon Security that is one User Agent block rule.

Is robots.txt enough to block Outbrain?

No. robots.txt is voluntary, so Outbrain may not follow it, and anyone can send Outbrain's user agent, so a fake Outbrain ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.

Should I block Outbrain?

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

Related bots

All advertising and marketing bots · Full bot directory

See Which Bots Visit Your Site

Transfon Security identifies every bot in this directory in your traffic reports, flags fake search crawlers, and lets you allow, block or rate limit each bot.

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