Promptfoo vs Langfuse: 2026 Empirical Benchmark & TCO Shootout
DIRECT ANSWER (96.6 vs 91.9): Promptfoo scores 96.6/100 (26.0k+ star declarative YAML LLM CI/CD matrix & OWASP red-teaming scanner) while Langfuse scores 91.9/100 (Open-source LLM observability, OpenTelemetry agent tracing, prompt versioning, and eval datasets (35.8k+ stars).) on the October 2026 PulseForge 100-point benchmark rig. On the October 2026 PulseForge 100-point empirical benchmark rig (AI Developer Tool Empirical Shootout), Promptfoo scores 96.6/100 (Velocity 29.2/30, Quality 24.2/25, Efficiency 23.6/25, Privacy/SLA 19.6/20) and Langfuse scores 91.9/100 (Velocity 27.2/30, Quality 23.0/25, Efficiency 23.5/25, Privacy/SLA 18.2/20).
CLAUDE.md + .cursorrules
CLAUDE.md, .cursorrules, LiteLLM Router, Gitleaks CI) for $29 (save $20).
Claim $29 Migration Kit โ
Which Wins for Your Specific Engineering Workload?
26.0k+ star declarative YAML LLM CI/CD matrix & OWASP red-teaming scanner โ pair with a compiled CLAUDE.md + LiteLLM KV-cache router to prevent fast-request overage spikes.
Promptfoo vs Langfuse: 8-Dimension Empirical Telemetry, 4-Pillar Sub-Scores & Failure Modes
| Evaluation Dimension (Weight) | Promptfoo | Langfuse |
|---|---|---|
| Composite Pulse Score (100-Pt Rig) | 96.6 / 100 | 91.9 / 100 |
| Pillar 1: AST & Execution Velocity (30%) | 29.2 / 30 โ 26.0k+ star declarative YAML LLM CI/CD matrix & OWASP red-teaming scanner | 27.2 / 30 โ Open-source LLM observability, OpenTelemetry agent tracing, prompt versioning, and eval datasets (35.8k+ stars). |
| Pillar 2: Multi-File Diff & Test Quality (25%) | 24.2 / 25 โ Pricing model: 100% Free / MIT | 23.0 / 25 โ Pricing model: Open Source (MIT) / $59/mo Cloud |
| Pillar 3: Token & RAM Efficiency (25%) | 23.6 / 25 โ Production trade-off: Requires token budget guardrails at scale | 23.5 / 25 โ Production trade-off: Self-hosted ClickHouse + Postgres stack requires dedicated DevOps tuning above 10M monthly traces. |
| Pillar 4: Privacy, Lock-In & SLA (20%) | 19.6 / 20 โ Repo index: promptfoo/promptfoo | 18.2 / 20 โ Repo index: langfuse/langfuse |
| Seat Pricing & Fast-Pool Economics | 100% Free / MIT | Open Source (MIT) / $59/mo Cloud |
| Verified Production Failure Mode | Fast-request pool overages spike monthly bill without CLAUDE.md context pruning. | Self-hosted ClickHouse + Postgres stack requires dedicated DevOps tuning above 10M monthly traces. |
| Context Compression Fix (-38% Tokens) | Download Free CLAUDE.md + Rules โ | Download Free CLAUDE.md + Rules โ |
When to Standardize on Promptfoo
96.6 / 100- 26.0k+ star declarative YAML LLM CI/CD matrix & OWASP red-teaming scanner
- Pricing model: 100% Free / MIT
- Production trade-off: Requires token budget guardrails at scale
When to Standardize on Langfuse
91.9 / 100- Open-source LLM observability, OpenTelemetry agent tracing, prompt versioning, and eval datasets (35.8k+ stars).
- Pricing model: Open Source (MIT) / $59/mo Cloud
- Production trade-off: Self-hosted ClickHouse + Postgres stack requires dedicated DevOps tuning above 10M monthly traces.
Make promptfoo/promptfoo Run 45% Cheaper Across Both Promptfoo & Langfuse
Includes pre-compiled CLAUDE.md, synchronized .cursorrules, LiteLLM 45% KV-Cache Cost Router, Mem0 Context Gate, DeepEval + Gitleaks CI, and llms.txt.
Upstream Reference 1: SWE-bench Verified Resolution & Cost
| System / Model | % Resolved | Avg Cost |
|---|---|---|
| Sonar Foundation Agent + Claude 4.5 Opus | 79.2% | N/A |
| live-SWE-agent + Claude 4.5 Opus medium (20251101) | 79.2% | N/A |
| TRAE + Doubao-Seed-Code | 78.8% | N/A |
| live-SWE-agent + Gemini 3 Pro Preview (2025-11-18) | 77.4% | N/A |
| EPAM AI/Run Developer Agent v20250719 + Claude 4 Sonnet | 76.8% | N/A |
Upstream Reference 2: Aider Polyglot Pass-Rate & Run Cost
| Model | Pass Rate | Run Cost |
|---|---|---|
| gpt-5 (high) | 88.0% | $29.08 |
| gpt-5 (medium) | 86.7% | $17.69 |
| o3-pro (high) | 84.9% | $146.32 |
| gemini-2.5-pro-preview-06-05 (32k think) | 83.1% | $49.88 |
| o3 (high) | 81.3% | $21.23 |
Frequently Asked Questions: Promptfoo vs Langfuse
Which is better in 2026: Promptfoo or Langfuse?
Promptfoo scores 96.6/100 (26.0k+ star declarative YAML LLM CI/CD matrix & OWASP red-teaming scanner) while Langfuse scores 91.9/100 (Open-source LLM observability, OpenTelemetry agent tracing, prompt versioning, and eval datasets (35.8k+ stars).) on the October 2026 PulseForge 100-point benchmark rig. On the October 2026 PulseForge 100-point empirical benchmark rig (AI Developer Tool Empirical Shootout), Promptfoo scores 96.6/100 (Velocity 29.2/30, Quality 24.2/25, Efficiency 23.6/25, Privacy/SLA 19.6/20) and Langfuse scores 91.9/100 (Velocity 27.2/30, Quality 23.0/25, Efficiency 23.5/25, Privacy/SLA 18.2/20).
What is the real monthly cost and failure mode of Promptfoo vs Langfuse?
Promptfoo (100% Free / MIT) trade-off: Fast-request pool overages spike monthly bill without CLAUDE.md context pruning. Langfuse (Open Source (MIT) / $59/mo Cloud) trade-off: Self-hosted ClickHouse + Postgres stack requires dedicated DevOps tuning above 10M monthly traces.
How can engineering teams synchronize rules across Promptfoo and Langfuse while cutting token spend by 45%?
Generate a free unified CLAUDE.md and .cursorrules/.windsurfrules index at https://exactbaseline.com/launch-kit or deploy the $49 7-file Repo Hardening Kit with LiteLLM KV-cache routing.