c-ares/c-ares

Health v2 · maintenance only

Adoption not part of the score

2196 stars · 708 forks observed · 2026-10-20

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

c-ares is a modern asynchronous DNS (stub) resolver library written in C. It provides non-blocking DNS query interfaces that abstract the intricacies of the DNS protocol, suitable for applications needing parallel or non-blocking resolution.

Use cases

• resolve hostnames asynchronously without blocking my event loop
• perform many DNS queries in parallel from a C application
• replace the unreliable system DNS resolver with a better one
• embed a DNS resolver in a cross-platform network application
• build a custom DNS client with support for modern RFCs
• resolve names on Windows, Linux, macOS, Android, and iOS with one library

When to choose

• you need non-blocking or parallel DNS resolution in C or C++
• you want a portable resolver that works consistently across operating systems
• you need a security-hardened, actively maintained, MIT-licensed DNS library
• you need modern DNS features like query caching, DNS cookies, or 0x20 encoding

When to avoid

• you only need simple synchronous lookups and are happy with your OS resolver
• you are working in a high-level language that already ships a capable async DNS client
• you need a full recursive/authoritative DNS server rather than a stub resolver

Facets

library · maturity stable

networking http-client developer-tools networking developer-tools apis windows cross-platform c cpp dns resolver async c-library stub-resolver linux macos

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