Langfuse v4
Langfuse v4 went GA for self-hosted deployments with 10x faster dashboards and new monitors/code evaluators.
Overview
Langfuse v4 became generally available for self-hosted deployments on August 17, 2026. It adds monitors for cost/quality/latency thresholds, code evaluators for deterministic checks, full-text search, a 'Pulse' metric visualization, a natural-language 'Langfuse Assistant', and Observations/Metrics API v2 -- cutting initial large-dataset table loads from seconds to milliseconds and making long-range dashboards load over 10x faster. Self-hosted v3 gets security patches through January 2027; Langfuse Cloud's forced v4 cutover is November 16, 2026.
This is a sourced directory entry. Features and capabilities are reported in the linked sources; this entry does not document independent Aymorphic testing.
Key features
- Cost/quality/latency threshold monitors
- Deterministic code evaluators
- Full-text search across traces
- Langfuse Assistant (natural-language queries)
- Observations API v2 / Metrics API v2
- 10x+ faster dashboard loads at scale
Use cases
- Self-hosted LLM observability at large trace volumes
- Automated quality/cost/latency alerting
- Natural-language exploration of trace data
Pricing
Open-source self-hosted (free) and Langfuse Cloud tiers; no new pricing announced with v4.
Pricing reflects the source record and may change. Confirm current terms with the provider.
Dates and sources
- Released
- 17 Aug 2026
- Record updated
- 23 Sept 2026
- Record last checked
- 23 Sept 2026