# nghttp3

> HTTP/3 library

**Wikidata**: [Q102489254](https://www.wikidata.org/wiki/Q102489254)  
**Source**: https://4ort.xyz/entity/nghttp3

## Summary
nghttp3 is a software library written in C that serves as an implementation of the HTTP/3 protocol. It is distributed as free software under the MIT License and is maintained by the ngtcp2 project. The library is actively developed, with its latest stable release tracking modern HTTP/3 standards through 2025.

## Key Facts
- **Entity Type:** Software library, Free software.
- **Primary Function:** Implementation of HTTP/3.
- **Aliases:** libnghttp3.
- **Programming Language:** C.
- **License:** MIT License.
- **Source Repository:** https://github.com/ngtcp2/nghttp3
- **Official Website:** https://nghttp2.org/nghttp3/
- **Dependencies:** Runs on/requires ngtcp2.
- **Latest Stable Version:** 1.9.0 (released 2025-04-16).

## FAQs
### Q: What is nghttp3 used for?
A: nghttp3 is a C library used to implement the HTTP/3 protocol in software applications. It provides the necessary functions to handle HTTP/3 traffic and is often used in conjunction with the ngtcp2 library.

### Q: Under what license is nghttp3 distributed?
A: nghttp3 is distributed as free software under the MIT License. This allows users to freely run, study, change, and distribute the software.

### Q: Where can the source code for nghttp3 be found?
A: The source code is hosted on GitHub at https://github.com/ngtcp2/nghttp3.

## Why It Matters
nghttp3 plays a critical role in the modern internet infrastructure by providing a robust, C-based implementation of HTTP/3, the latest major revision of the HTTP network protocol. As the web transitions away from TCP-based protocols to UDP-based QUIC for improved performance and reduced latency, libraries like nghttp3 become essential for servers, clients, and proxies to communicate effectively.

Because it is released under the permissive MIT License, it is highly accessible for integration into both open-source and proprietary software ecosystems. Its compatibility with the C programming language ensures that it can be embedded in a wide variety of systems, from high-performance servers to embedded devices. The library's active development cycle—evidenced by frequent stable releases—ensures that it remains compliant with evolving standards and security practices.

## Notable For
- **HTTP/3 Implementation:** Specifically designed to implement the HTTP/3 protocol stack.
- **C Language:** Built using C (Q15777), making it highly portable and performant.
- **Active Development:** Maintains a frequent release schedule, with stable versions extending into 2025.
- **MIT License:** Offers a permissive licensing model for broad commercial and non-commercial use.
- **Ecosystem Integration:** Functions as a core component alongside ngtcp2 in the ngtcp2 project ecosystem.

## Body

### Technical Overview
nghttp3 is a software library classified as "free software," designed to facilitate the use of the HTTP/3 protocol. It is identified in software repositories and package managers (such as MacPorts and SlackBuilds) by the name `nghttp3`. The library is implemented in the C programming language and is authored by the ngtcp2 organization.

### Licensing and Status
The project is fully copyrighted but distributed freely under the MIT License. This classification allows users to utilize, modify, and redistribute the code under the terms defined by the license. The software is categorized as an "instance of" a software library and is a distinct implementation of HTTP/3.

### Version History and Releases
The development of nghttp3 is characterized by a steady stream of stable releases. The project follows a versioning scheme that tracks its progression from initial stability to recent updates.

- **Initial Stable Release:** Version 1.0.0 was released on October 15, 2023.
- **Subsequent Updates:**
    - **v1.1.0:** Released November 26, 2023.
    - **v1.2.0:** Released February 17, 2024.
    - **v1.3.0:** Released May 9, 2024.
    - **v1.4.0:** Released June 13, 2024.
    - **v1.5.0:** Released August 24, 2024.
    - **v1.6.0:** Released October 5, 2024.
    - **v1.7.0:** Released December 19, 2024.
    - **v1.8.0:** Released February 21, 2025.
- **Latest Recorded Version:** Version 1.9.0 was released on April 16, 2025.

### Project Relationships
nghttp3 is closely related to the **ngtcp2** project. In the knowledge base, ngtcp2 is listed as a requirement ("Runs on / Requires") for nghttp3. The source code is hosted within the ngtcp2 organization on GitHub, and the official website is hosted at nghttp2.org/nghttp3/. The library is also available through various software distribution channels, including MacPorts and SlackBuilds.

## References

1. [Source](https://api.github.com/repos/ngtcp2/nghttp3)
2. [The nghttp3 Open Source Project on Open Hub: Languages Page. Open Hub](https://www.openhub.net/p/nghttp3/analyses/latest/languages_summary)
3. [Release 1.0.0. 2023](https://github.com/ngtcp2/nghttp3/releases/tag/v1.0.0)
4. [Release 1.1.0. 2023](https://github.com/ngtcp2/nghttp3/releases/tag/v1.1.0)
5. [Release 1.2.0. 2024](https://github.com/ngtcp2/nghttp3/releases/tag/v1.2.0)
6. [Release 1.3.0. 2024](https://github.com/ngtcp2/nghttp3/releases/tag/v1.3.0)
7. [Release 1.4.0. 2024](https://github.com/ngtcp2/nghttp3/releases/tag/v1.4.0)
8. [Release 1.5.0. 2024](https://github.com/ngtcp2/nghttp3/releases/tag/v1.5.0)
9. [Release nghttp3 v1.6.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.6.0)
10. [Release nghttp3 v1.7.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.7.0)
11. [Release nghttp3 v1.8.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.8.0)
12. [Release nghttp3 v1.9.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.9.0)
13. [Release nghttp3 v1.10.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.10.0)
14. [Release nghttp3 v1.10.1 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.10.1)
15. [Release nghttp3 v1.11.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.11.0)
16. [Release nghttp3 v1.12.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.12.0)
17. [Release nghttp3 v1.13.0 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.13.0)
18. [Release nghttp3 v1.13.1 · ngtcp2/nghttp3](https://github.com/ngtcp2/nghttp3/releases/tag/v1.13.1)
19. [Release 1.14.0. 2025](https://github.com/ngtcp2/nghttp3/releases/tag/v1.14.0)
20. [Release 1.15.0. 2026](https://github.com/ngtcp2/nghttp3/releases/tag/v1.15.0)