4chan is a simple image-based bulletin board where anyone can post comments and share images across topic-specific boards. 4chan exposes a read-only JSON API (launched September 2012) that serves the same board, thread, catalog, and archive data consumed by the public site via static JSON files at a.4cdn.org. The API supports GET/HEAD/OPTIONS only — there is no posting, authentication, or write surface.
4chan publishes 6 APIs on the APIs.io network, including Archive API, Boards API, Catalog API, and 3 more. Tagged areas include Social, Bulletin Board, Imageboard, Read Only, and JSON.
The 4chan catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.
4chan’s developer surface includes documentation, tooling, and 20 more developer resources.
aid: 4chan
name: 4chan
description: 4chan is a simple image-based bulletin board where anyone can post comments and share images across topic-specific
boards. 4chan exposes a read-only JSON API (launched September 2012) that serves the same board, thread, catalog, and archive
data consumed by the public site via static JSON files at a.4cdn.org. The API supports GET/HEAD/OPTIONS only — there is
no posting, authentication, or write surface.
url: https://github.com/4chan/4chan-API
accessModel:
pricing: freemium
onboarding: unknown
trial: false
try_now: false
public: false
label: Freemium
confidence: medium
source:
- plans
generated: '2026-07-22'
method: derived
image: https://s.4cdn.org/image/fp/logo-transparent.png
specificationVersion: '0.20'
created: '2026-05-28'
modified: '2026-05-28'
x-source: public-apis/public-apis
x-type: company
x-category: Social
x-tier: 2
x-tier-reason: documented-read-only-json-api-with-active-community-clients
tags:
- Social
- Bulletin Board
- Imageboard
- Read Only
- JSON
- Public APIs
- Community
apis:
- aid: 4chan:4chan-archive-api
name: 4chan Archive API
description: Per-board list of OP numbers for closed, archived threads.
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Archive
properties:
- type: OpenAPI
url: openapi/4chan-archive-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
- aid: 4chan:4chan-boards-api
name: 4chan Boards API
description: List of all boards on 4chan and 4channel and their per-board settings.
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Boards
properties:
- type: OpenAPI
url: openapi/4chan-boards-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
- aid: 4chan:4chan-catalog-api
name: 4chan Catalog API
description: Per-board catalog snapshot containing every OP and its preview replies, grouped by index page.
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Catalog
properties:
- type: OpenAPI
url: openapi/4chan-catalog-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
- aid: 4chan:4chan-indexes-api
name: 4chan Indexes API
description: Per-board, per-page index document of threads (each with a posts array including the OP and a small number
of preview replies).
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Indexes
properties:
- type: OpenAPI
url: openapi/4chan-indexes-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
- aid: 4chan:4chan-threadlist-api
name: 4chan Threadlist API
description: Per-board summary list of every live thread (id, last-modified, reply count) grouped by index page.
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Threadlist
properties:
- type: OpenAPI
url: openapi/4chan-threadlist-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
- aid: 4chan:4chan-threads-api
name: 4chan Threads API
description: Single-thread document containing the OP and every reply.
humanURL: https://github.com/4chan/4chan-API
baseURL: https://a.4cdn.org
tags:
- Threads
properties:
- type: OpenAPI
url: openapi/4chan-threads-api-openapi.yml
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: Signup
url: https://github.com/4chan/4chan-API#api-rules
- type: Support
url: mailto:api@4chan.org
- type: TermsOfService
url: https://github.com/4chan/4chan-API#api-terms-of-service
common:
- type: AgenticAccess
url: agentic-access/4chan-agentic-access.yml
- type: VulnerabilityDisclosure
url: security/4chan-vulnerability-disclosure.yml
- type: DomainSecurity
url: security/4chan-domain-security.yml
- type: Website
url: https://www.4chan.org
- type: Documentation
url: https://github.com/4chan/4chan-API
- type: GitHubOrganization
url: https://github.com/4chan
- type: SourceCode
url: https://github.com/4chan/4chan-JS
title: 4chan native browser extension source
- type: ContactEmail
url: mailto:api@4chan.org
- type: Tools
title: MCP Server (community, unofficial)
url: https://github.com/sh0n0/chan-mcp-server
- type: SDKs
title: Python Wrapper (BASC-py4chan, community)
url: https://github.com/bibanon/BASC-py4chan
- type: SDKs
title: Python Wrapper (py-4chan, community)
url: https://github.com/e000/py-4chan
- type: SDKs
title: Node.js Client (4chanjs, community)
url: https://github.com/yocontra/4chanjs
- type: SDKs
title: Go Client (go-4chan-api, community)
url: https://github.com/moshee/go-4chan-api
- type: SDKs
title: Rust Client (rchan, community)
url: https://github.com/insomnimus/rchan
- type: SDKs
title: Racket Client (yotsubAPI, community)
url: https://github.com/g-gundam/yotsubAPI
- type: Tools
title: BA Thread Archiver (community)
url: https://github.com/hydrusnetwork/BA-4chan-thread-archiver
- type: PublicAPIsListing
url: https://github.com/public-apis/public-apis
- type: Plans
url: plans/4chan-plans-pricing.yml
- type: RateLimits
url: rate-limits/4chan-rate-limits.yml
- type: Vocabulary
url: vocabulary/4chan-vocabulary.yml
- type: SpectralRules
url: rules/4chan-rules.yml
- type: JSONLD
url: json-ld/4chan-context.jsonld
features:
- name: Read-Only JSON Catalog
description: Static JSON representations of boards, threads, catalogs, and archives are served from a.4cdn.org; clients
use standard HTTP semantics including If-Modified-Since for caching.
- name: No Authentication
description: The API requires no API key, no token, and no account; it is fully anonymous and serves the same data visible
to anonymous web visitors.
- name: HTTP Caching Built In
description: The API requires clients to send If-Modified-Since headers on repeated requests, allowing 304 Not Modified
responses and reducing server load.
- name: CORS Restricted to 4chan Origins
description: CORS is enabled but only for origins boards.4chan.org and boards.4channel.org via HTTP or HTTPS; only GET/OPTIONS/HEAD
methods are accepted.
- name: Per-Board Catalog
description: Every board (a, b, g, pol, po, etc.) exposes catalog, threadlist, archive, and per-page index endpoints with
the same shape, making bulk crawling trivial.
- name: Static Media Domains
description: User-uploaded images and thumbnails live at i.4cdn.org/{board}/{tim}.{ext}; static site assets including flags,
spoiler images, and capcode icons live at s.4cdn.org.
useCases:
- name: Read-Only Board Crawlers
description: Build research crawlers that periodically snapshot board catalogs, threads, and archives while respecting the
1 request per second limit and 10 second per-thread refresh floor.
- name: Thread Archivers
description: Mirror archived threads and their attached media to durable storage for academic study or cultural preservation
(see BA Thread Archiver, Ayase / Asagi).
- name: Imageboard Analytics
description: Use threads.json and catalog.json to chart posting volume, reply velocity, and moderator/admin capcode activity
across boards over time.
- name: Language Models and Markov Chains
description: Feed cleaned post comments from catalog.json and thread.json into text generation experiments (see 4chanMarkovText).
- name: Static Site Mirrors
description: Combine boards.json + per-board catalog/thread JSON to build static site mirrors of individual threads suitable
for read-only display.
integrations:
- name: BASC-py4chan
description: Python wrapper providing Pythonic access to boards, threads, and posts.
- name: 4chanjs
description: Node.js and browser client for the 4chan JSON API.
- name: go-4chan-api
description: Go client for crawling and consuming 4chan board JSON.
- name: rchan
description: Rust crate exposing typed boards/threads/posts and a basic client.
- name: Ayase / Asagi
description: Archive middleware that ingests 4chan JSON and stores posts in SQL for replay.
- name: chan-mcp-server (community)
description: Unofficial Model Context Protocol server exposing 4chan boards/threads/catalog as MCP tools.
solutions:
- name: Imageboard Research Archive
description: Combine threads.json polling with archive.json snapshots and i.4cdn.org media downloads to build a long-term
archive that respects the published rate limits.
- name: Capcode Activity Dashboard
description: Use catalog.json/thread.json capcode and id fields to surface moderator and admin activity per board over time.
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
Kin Score
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