Fastify 4+Node.js 26

Why?

Why is Fastify 4 incompatible with Node.js 26?

Requirement

Node.js 14.x || 16.x || 18.x || 20.x || 22.x

Selected version

Node.js 26

Evaluation

26.8.1 does not satisfy 14.x || 16.x || 18.x || 20.x || 22.x

Conclusion

INCOMPATIBLE

Evidence

CompatHub reports compatibility from upstream sources rather than making unsupported claims of its own.

• Fastify LTS Schedule

  Confidence: HIGH

  https://github.com/fastify/fastify/blob/main/docs/Reference/LTS.md

  Retrieved 3 September 2026

  Requirement: 14.x || 16.x || 18.x || 20.x || 22.x

Node.js versions

Compatibility is derived from the project's declared Node.js requirement (14.x || 16.x || 18.x || 20.x || 22.x); it does not mean every version combination has been independently tested.

• 13❌
• 14✓
• 15❌
• 16✓
• 17❌
• 18✓
• 19❌
• 20✓
• 21❌
• 22✓
• 23❌
• 24❌
• 25❌
• 26❌
• 27—

Other Node.js versions satisfying this requirement

Fastify 4 — compatible Node.js lines tracked in CompatHub

• ✓Node.js 14version lineEOL
• ✓Node.js 16version lineEOL
• ✓Node.js 18version lineEOL
• ✓Node.js 20version lineEOL
• ✓Node.js 22version linesupported

Other Fastify versions

Only lines with relevant compatibility evidence are listed.

• Fastify 5
• Fastify 4
• Fastify 3
• Fastify 2
• Fastify 1
• Fastify 0.43
• Fastify 0.42
• Fastify 0.41
• Fastify 0.40
• Fastify 0.39
• Fastify 0.38
• Fastify 0.37
• Fastify 0.36
• Fastify 0.35
• Fastify 0.34
• Fastify 0.33
• Fastify 0.32
• Fastify 0.31

Lifecycle context

Lifecycle status is separate from compatibility. An EOL component can still satisfy a documented version requirement.