React SSR and hydration
Core · React SSR
Core principle — Use server rendering to deliver useful HTML without turning hydration into an invisible second application.A render path with explicit data ownership, hydration assumptions, and recovery behavior.
Key concepts
Server
HTML and initial data
Client
Events and local state
Failure
Fallback and status
Boundary model
Ownership matrix
Engineering considerations
SSR performance is determined by data dependencies, serialization, cache behavior, and client takeover—not only render speed.Design constraint SSR is a contract between two runtimes: server output and browser continuation.
Implementation notes
Decision lens
Related topics
Add streaming
Read the focused guide for this boundary.
Evaluate RSC
Read the focused guide for this boundary.
Coordinate cache
Read the focused guide for this boundary.
- stream · Add streaming — Read the focused guide for this boundary.
- atom · Evaluate RSC — Read the focused guide for this boundary.
- layer-group · Coordinate cache — Read the focused guide for this boundary.