# h2o/picohttpparser

tiny HTTP parser written in C (used in HTTP::Parser::XS et al.)

Repository: https://github.com/h2o/picohttpparser
Canonical: https://ross.abutalabs.com/products/picohttpparser
Language: C
License Family: other
Last push: 2026-04-06T05:31:48+00:00

## Health v2 (maintenance only)
Score: 66/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 76, release rhythm 35, longevity 100
- inputs: {"age_days": 6174, "days_push": 149, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2103, forks 273 (observed 2026-08-28T04:06:13.762622+00:00)

## What it is
PicoHTTPParser is a tiny, fast HTTP request/response parser written in C. It is stateless and allocation-free, setting pointers into the caller's buffer instead of copying data, and is widely embedded in projects like H2O and Perl modules such as Plack and Starman.

## Use cases
- parse http requests in c
- fast zero-allocation http parser
- parse http response headers
- decode chunked transfer encoding
- embed http parsing in a server
- incremental parsing of partial http data

## When to choose
- you need a minimal, extremely fast HTTP/1 parser in C or C++
- you want zero memory allocations and stateless parsing
- you need incremental parsing of data arriving in chunks
- you are building a high-performance HTTP server or client

## When to avoid
- you need HTTP/2 or HTTP/3 support
- you want a high-level API that allocates parsed structures for you
- you need a parser in a higher-level language without C bindings
- you require a permissive license with an explicit file (licensing is dual Perl/MIT but no dedicated LICENSE file)

## Facets
- artifact type: library
- maturity: stable
- function: parser, http-server, http-client
- domain: web-development, backend, apis, performance
- platform: cpp, c, cross-platform, windows
- tags: http, http-parser, zero-allocation, stateless, c-library, http1, chunked-encoding, linux, macos

## Member repositories
- h2o/picohttpparser (main) score 66

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:13.762622+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:54:14.850618+00:00, confidence not recorded.
  - readme: https://github.com/h2o/picohttpparser (fetched 2026-08-28T04:06:13.762622+00:00, sha 43683b713b42)
- Data as of 2026-08-30T08:39:29.467469+00:00.