codeforces.com Review

TitletagDescriptiontaglanguage
Codeforces English
Alexarank
3133
Ip adress104.26.6.164Nameserverjean.ns.cloudflare.com
fred.ns.cloudflare.com
Status code200
robots.txt -http://codeforces.com/robots.txt
 # As a condition of accessing this website, you agree to abide by the following
# content signals:

# (a)  If a content-signal = yes, you may collect content for the corresponding
#      use.
# (b)  If a content-signal = no, you may not collect content for the
#      corresponding use.
# (c)  If the website operator does not include a content signal for a
#      corresponding use, the website operator neither grants nor restricts
#      permission via content signal with respect to the corresponding use.

# The content signals and their meanings are:

# search:   building a search index and providing search results (e.g., returning
#           hyperlinks and short excerpts from your website's contents). Search does not
#           include providing AI-generated search summaries.
# ai-input: inputting content into one or more AI models (e.g., retrieval
#           augmented generation, grounding, or other real-time taking of content for
#           generative AI search answers).
# ai-train: training or fine-tuning AI models.

# ANY RESTRICTIONS EXPRESSED VIA CONTENT SIGNALS ARE EXPRESS RESERVATIONS OF
# RIGHTS UNDER ARTICLE 4 OF THE EUROPEAN UNION DIRECTIVE 2019/790 ON COPYRIGHT
# AND RELATED RIGHTS IN THE DIGITAL SINGLE MARKET.

# BEGIN Cloudflare Managed content

User-Agent: *
Content-signal: search=yes,ai-train=no
Allow: /

User-agent: Amazonbot
Disallow: /

User-agent: Applebot-Extended
Disallow: /

User-agent: Bytespider
Disallow: /

User-agent: CCBot
Disallow: /

User-agent: ClaudeBot
Disallow: /

User-agent: Google-Extended
Disallow: /

User-agent: GPTBot
Disallow: /

User-agent: meta-externalagent
Disallow: /

# END Cloudflare Managed Content

HTTP/1.1 301 Moved Permanently
Date: Wed, 07 Jan 2026 04:51:38 GMT
Content-Length: 0
Connection: keep-alive
Location: https://codeforces.com/
Vary: accept-encoding
Report-To: {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=1ZLC8%2FZscsnd2pq0JSUI5wSMEvPAc6%2Bc%2Bu51iPHKhCSxHxHjAD0ps%2F80qM6KT%2FopbDNzM%2FPa9dUHiiR880fLx9sV%2BWwCBx1SmTQnf2s%3D"}]}
Nel: {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
Server-Timing: cfEdge;dur=3,cfOrigin;dur=0
Server: cloudflare
CF-RAY: 9ba0d7544edacb50-NRT
alt-svc: h3=":443"; ma=86400

HTTP/1.1 200 OK
Date: Wed, 07 Jan 2026 04:51:38 GMT
Content-Type: text/html;charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Server: cloudflare
Nel: {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
Vary: Accept-Encoding
vary: accept-encoding
Set-Cookie: JSESSIONID=C112FDBB9411C9760FCFC17C7C63FB0E; Path=/; HttpOnly; SameSite=Lax
Set-Cookie: 39ce7=CFUOEog2; Max-Age=1000000; Path=/; Secure=false; SameSite=Lax
Set-Cookie: 39ce7=CFUOEog2; Max-Age=1000000; Expires=Sun, 18 Jan 2026 18:38:18 GMT; Path=/; SameSite=Lax
X-Robots-Tag: noai
X-Robots-Tag: noai
X-Req-Id: neo:9ba0d7548bf4781c-NRT:/
Cache-Control: private,no-cache,no-store,max-age=0,must-revalidate
Expires: -1
Pragma: no-cache
Strict-Transport-Security: max-age=86400
X-XSS-Protection: 1; mode=block
X-Frame-Options: sameorigin
X-Content-Type-Options: nosniff
Report-To: {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=ZgU1TL%2FKfyxu%2FBG1loA%2FIrmb8jBh8V8Y57%2BgELR7HX9LSngYAbVq13TfOto3Y2GGf23JmEtdojTtihXTwlcYiX2wEWGAp3JOzoee7EE%3D"}]}
cf-cache-status: DYNAMIC
Server-Timing: cfCacheStatus;desc="DYNAMIC"
Server-Timing: cfEdge;dur=6,cfOrigin;dur=315
Content-Encoding: br
CF-RAY: 9ba0d7548bf4781c-NRT
alt-svc: h3=":443"; ma=86400

iframe