curl is a bot in the HTTP clients and libraries category, operated by curl project.
curl is a command line tool and library for making HTTP requests. Its default user agent is sent by shell scripts, health checks and quick scrapers.
HTTP clients are programming libraries and command line tools. Developers use them for scripts, integrations and scrapers. Real browsers never send these user agents, so treat them as automated traffic and block them on pages meant for people.
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.
Share of curl requests to sites protected by Transfon Security in the 7 days to 27 October 2026.
| United States | 47% |
| United Kingdom | 35% |
| Ireland | 8% |
| Hong Kong | 2% |
| South Africa | 2% |
| The Netherlands | 2% |
| Amazon.com, Inc. AS16509 | 42% |
| LLC VASH KREDIT BANK AS209630 | 32% |
| OVH SAS AS16276 | 8% |
| Microsoft Corporation AS8075 | 3% |
| Dimension Data AS20011 | 2% |
curl does not read robots.txt. The rules below record your policy, but they will not stop it. To actually block curl, use a WAF rule as shown in the next section.
User-agent: curl Disallow: /
User-agent: curl Disallow: /private/ Disallow: /search
User-agent: curl Allow: /blog/ Disallow: /
User-agent: curl Allow: / User-agent: * Disallow: /
User-agent: curl group, curl ignores your User-agent: * rules, so repeat any that should still apply.curl from curl's user agent; check curl project's own documentation if it publishes a different robots.txt name.Treat robots.txt as a statement of your policy, and enforce it where requests arrive.
curl is a common tool for scrapers. Real readers never use it, so block it on article pages and keep it out of ad requests.
Transfon Security for publishersTraffic from curl on landing pages is automated. It inflates clicks and visits, so filter it from campaign data and raise it with the ad network.
Transfon Security for advertisersPrice scrapers, stock checkers and card testing scripts often run on curl. Block it on product, cart and checkout pages.
Transfon Security for e-commercecurl is normal for API clients but not for your web app. Allow it only on API routes that need a key, and rate limit it there.
Transfon Security for SaaS and APIscurl ignores robots.txt, so it has to be stopped when the request arrives. Transfon Security shows curl 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
curl is a bot in the HTTP clients and libraries category, operated by curl project. curl is a command line tool and library for making HTTP requests. Its default user agent is sent by shell scripts, health checks and quick scrapers.
No. curl does not follow robots.txt, so a Disallow rule will not stop it. Block it by user agent at your server, CDN or WAF instead.
Block requests whose user agent contains "curl/" at your server, CDN or WAF, because curl does not read robots.txt. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so curl may not follow it, and anyone can send curl's user agent, so a fake curl ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.
HTTP clients are programming libraries and command line tools. Developers use them for scripts, integrations and scrapers. Real browsers never send these user agents, so treat them as automated traffic and block them on pages meant for people.
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.
Privacy, security, monetization, and performance insights. A few emails a month, no spam.