reliable

At a glance

• Editor score
  6.3 / 10
• Pricing
  Open source
• Best for
  Developers implementing reliable UDP primitives
• Paid from
  Free
• Facts checked
  21 Sep 2026

• Where it wins

  • Tracks acknowledgements, sequence numbers, and duplicate packets
  • Handles packet fragmentation, reassembly, jitter, and packet loss
  • Provides endpoint APIs for sending and receiving UDP packets

• Where it doesn't

  • Requires developers to build around their own socket layer
  • Does not provide matchmaking, relay services, or a hosted backend
  • Its scope is limited to UDP networking primitives

Our verdict on reliable

reliable is an open-source C library for developers building multiplayer games and other real-time networked applications. It adds packet acknowledgement to UDP-based protocols while leaving the surrounding networking architecture in the developer’s hands. The library includes acknowledgement tracking, packet fragmentation and reassembly, duplicate-packet detection and dropping, endpoint APIs, and access to packet sequence numbers and acknowledgements. It is intended for teams creating their own low-level network layer rather than looking for a complete multiplayer service.

The open-source pricing model makes reliable suitable for projects that need a focused UDP component without a hosted service model. Its technical scope centers on UDP transport, with netcode listed as an integration. The published feature set also includes round-trip-time, jitter, and packet-loss estimates, giving developers network measurements alongside acknowledgement handling. That combination fits applications where packet delivery behavior and protocol control need to remain close to the game or application’s own socket implementation.

The trade-off is narrow scope. reliable is a component, not a messaging layer, matchmaking service, relay, or hosted game backend, so teams need other systems for those responsibilities. It also does not target developers who want an end-to-end multiplayer networking stack with built-in service infrastructure. Choose reliable when the priority is implementing acknowledgement, fragmentation, duplicate detection, and endpoint control over UDP; choose a broader alternative when matchmaking, relays, hosted sessions, or a complete multiplayer backend are central requirements.

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reliable pricing

reliable fact sheet

reliable integrations

reliable lists 1 integrations on its own site.

• netcode

Alternatives to reliable

• ColyseusFlexible multiplayer middleware spanning networking, matchmaking, accounts, persistence, and live operations.9.4
• SmartFoxServerA broad, mature backend for studios building real-time multiplayer games.9.2
• Photon QuantumA focused Unity framework for deterministic simulation, rollback, and authoritative validation.9.0

See all reliable alternatives →

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update