cpp-httplib
A single-header C++11 library for building HTTP/HTTPS servers and clients.
- Stars
- 17k
- Forks
- 2.8k
- Licence
- MIT
- Language
- C++
- Last update
- 6 days ago
- Type
- Library
What it is
cpp-httplib is a C++ library you add to a project by including one header file, httplib.h. It lets a C++ program act as a web server or as a web client that sends HTTP and HTTPS requests. It uses blocking socket I/O and supports HTTP/1.1 only, and it can use OpenSSL, Mbed TLS, or wolfSSL for encryption.
- Run a small HTTP server in a C++ program that responds to GET requests
- Make HTTP or HTTPS requests from a C++ program to an external API
- Set up mutual TLS so a server verifies client certificates
- Stream responses or use Server-Sent Events and WebSocket endpoints
Great for
- C++ developers who need a simple embedded HTTP server or client without a large framework
- Projects that want to avoid a complex build setup by using a single header file
- Teams that need HTTPS with a choice of OpenSSL, Mbed TLS, or wolfSSL
- Developers who want WebSocket, Server-Sent Events, or a stream API from the same library
Not ideal for
- Apps that need non-blocking, high-concurrency socket I/O, since the README says this is blocking I/O and not the right choice for that
- Projects that need HTTP/2 or HTTP/3, which the README says are not implemented
- Targets that are 32-bit, since the README says 32-bit platforms are not supported and security reports for them are closed
How to get it
- 1
Clone and build from source
You'll need: A C++11 or later compiler · OpenSSL 3.0 or later, Mbed TLS, or wolfSSL if you need HTTPS
Clone the repository
git clone https://github.com/yhirose/cpp-httplib - 2
Run it
- Include httplib.h from the cloned repository in your C++ source file
- Create an httplib::Server object and register a route with Get
- Call svr.listen("0.0.0.0", 8080) to start serving
- Open http://localhost:8080/hi in a browser or with curl to check the response
- 3
Get the most out of it
- Use the SSL/TLS support section to set up HTTPS with httplib::SSLServer and a certificate and key
- Use set_ca_cert_path and the verification settings to control how a client checks server certificates
- Set up mutual TLS by passing a client CA to the server and client certificate files to the client
- Use the SSL error handling methods ssl_error and ssl_backend_error to diagnose failed requests
- Read the linked stream, Server-Sent Events, and WebSocket guides for those features
Downloads
Strengths
- Distributed as a single header file, so setup is just an include
- Supports HTTPS through three TLS backends: OpenSSL, Mbed TLS, and wolfSSL
- Documentation covers TLS error handling, custom certificate verification, and mutual TLS
Trade-offs
- Blocking socket I/O and HTTP/1.1 only, which rules out some workloads
- The README warns that 32-bit platforms are unsupported and not security reviewed
- Some TLS behavior differs by backend, such as wolfSSL's certificate enumeration limits, so the docs must be read per backend
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| cpp-httplib (this) | 17k | Library | beginner | 6 days ago | C++ developers who need a simple embedded HTTP server or client without a large framework |
| got | 15k | Library | beginner | 7 days ago | Node.js developers who call web APIs from server-side code |
| entt | 13.2k | Library | advanced | 4 days ago | C++ game developers who want an ECS |
| modern-cpp-tutorial | 25.9k | Learning resource | intermediate | 29 days ago | Experienced C++ developers who want a quick overview of modern features |
| json | 50.8k | Library | beginner | 4 days ago | C++ developers who need to read or write JSON in an application |
| axum | 27.7k | Library | intermediate | 4 days ago | Rust developers building HTTP APIs or web services |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.