Langfuse
Open-source LLM engineering platform for collaborative debugging and analysis.
About Langfuse
Langfuse is a cutting-edge open-source LLM engineering platform that has revolutionized the way teams debug, analyze, and iterate on their language model applications in 2026. Designed for collaborative work, Langfuse offers a comprehensive suite of tools that enhance the performance of language models by providing robust observability, metrics, prompt management, and evaluation capabilities. As the demand for efficient and reliable LLM applications continues to grow, Langfuse stands out as a leader in the industry, trusted by numerous Fortune 500 companies. The platform's open-source nature allows for unparalleled customization and flexibility, making it an ideal choice for both small teams and large enterprises. With a strong emphasis on security and data privacy, Langfuse ensures that users can confidently develop and deploy LLM applications without compromising on safety. Whether you're a developer looking to optimize your AI models or a business aiming to leverage advanced language processing technologies, Langfuse provides the tools and support necessary to achieve your goals. Its integration capabilities with popular LLM libraries and frameworks further enhance its appeal, solidifying its position as a must-have tool in the AI development landscape of 2026.
Langfuse Key Features
Observability
Langfuse provides comprehensive observability tools that allow teams to capture complete traces of their LLM applications and agents. This feature is crucial for identifying and diagnosing failures, enabling developers to build robust evaluation datasets. By leveraging OpenTelemetry, Langfuse supports all popular LLM and agent libraries, ensuring seamless integration and monitoring.
Metrics
Langfuse offers detailed metrics that help teams understand the performance of their language models. These metrics provide insights into model efficiency, accuracy, and resource utilization, allowing teams to make data-driven decisions to optimize their applications. The platform's metrics feature is essential for continuous improvement and maintaining high-performance standards.
Prompt Management
The prompt management feature in Langfuse allows teams to efficiently manage and iterate on their prompts. This tool enables users to test different prompt variations and analyze their impact on model outputs, facilitating the development of more effective and contextually appropriate prompts. It is a valuable asset for teams looking to refine their LLM interactions.
Evaluation
Langfuse's evaluation tools provide a structured approach to assessing the performance of language models. By offering capabilities for automated and manual evaluations, teams can systematically measure model outputs against predefined criteria, ensuring that their applications meet desired quality standards. This feature is critical for maintaining the reliability and accuracy of LLM applications.
Human Annotation
This feature allows teams to incorporate human feedback into their model evaluation processes. By enabling human annotation, Langfuse helps teams gather qualitative insights and improve model performance through real-world feedback. This integration of human judgment is essential for refining models and ensuring they align with user expectations.
Playground
The Langfuse Playground provides an interactive environment for testing and experimenting with language models. Users can quickly prototype and iterate on their ideas, gaining immediate feedback on model behavior. This feature is particularly useful for developers and researchers who need a flexible space to explore new concepts and approaches.
Public API
Langfuse offers a robust public API that allows developers to integrate its features into their existing workflows. This API provides access to all core functionalities, enabling seamless automation and customization. The public API is a key component for teams looking to extend Langfuse's capabilities and tailor them to specific project needs.
SDKs for Python and JS/TS
Langfuse provides software development kits (SDKs) for Python and JavaScript/TypeScript, making it easy for developers to integrate Langfuse into their applications. These SDKs offer pre-built functions and utilities that simplify the process of adding observability and evaluation features to LLM applications, enhancing developer productivity and reducing integration time.
Langfuse Pricing Plans (2026)
Hobby
- LLM Application & Agent Tracing
- Prompt Management
- Evaluation
- Public API
- Community support via GitHub
- 50k units/month included
- 30 days data access
- 2 users
Core
- 100k units/month included
- 90 days data access
- Unlimited users
- In-app support
- Additional usage costs $8/100k units
- Lower rate limits compared to Pro
Pro
- Unlimited history
- High rate limits
- All platform features
- SOC2 & ISO27001 reports
- Additional usage costs $8/100k units
- Optional Teams Add-on for $300/month
Enterprise
- Custom rate limits
- Audit Logs
- SCIM API
- Dedicated support engineer
- Requires contact with sales for setup
- Custom terms and pricing
Langfuse Pros
- + Open-source platform allows for extensive customization and flexibility.
- + Comprehensive observability and metrics enhance debugging and optimization.
- + Robust prompt management tools improve model performance and user satisfaction.
- + Seamless integration with popular LLM libraries and frameworks.
- + Strong security and compliance features ensure data protection.
- + Extensive support and documentation facilitate ease of use and implementation.
Langfuse Cons
- − May require technical expertise to fully leverage all features.
- − Initial setup can be complex for users unfamiliar with LLM platforms.
- − Some advanced features may have a learning curve.
- − Free tier has usage limitations that may not suffice for larger projects.
- − Enterprise pricing may be high for smaller organizations.
Langfuse Use Cases
Debugging LLM Applications
Teams use Langfuse to debug complex language model applications by capturing detailed traces and metrics. This enables them to identify bottlenecks and errors, improving the reliability and performance of their applications.
Optimizing Prompt Design
Langfuse's prompt management tools allow content creators and developers to experiment with different prompt structures, leading to more effective and engaging interactions with language models.
Performance Evaluation
Researchers and developers utilize Langfuse's evaluation tools to systematically assess model outputs, ensuring that their applications meet quality benchmarks and deliver accurate results.
Incorporating Human Feedback
Product teams use the human annotation feature to gather real-world feedback on model outputs, allowing them to refine and improve their applications based on user input.
Rapid Prototyping
The Playground feature is used by developers to quickly prototype and test new ideas, facilitating innovation and experimentation in language model applications.
Custom Workflow Integration
Enterprises leverage Langfuse's public API to integrate its features into their custom workflows, enhancing automation and streamlining processes across their development pipelines.
What Makes Langfuse Unique
Open Source Platform
Langfuse's open-source nature allows for extensive customization and community-driven improvements, setting it apart from proprietary solutions.
Comprehensive Observability
The platform's integration with OpenTelemetry and support for popular LLM libraries provide unmatched observability capabilities, crucial for debugging and performance optimization.
Integrated Human Annotation
Langfuse's ability to incorporate human feedback into the evaluation process offers a unique advantage in refining model outputs based on real-world insights.
Extensive SDK Support
With SDKs for both Python and JS/TS, Langfuse ensures easy integration and broad compatibility, catering to a wide range of development environments.
Who's Using Langfuse
Enterprise Teams
Enterprise teams use Langfuse to enhance the reliability and performance of their large-scale LLM applications, benefiting from its robust observability and evaluation tools.
Research Institutions
Research institutions leverage Langfuse to conduct detailed evaluations of language models, using its comprehensive metrics and human annotation features to advance their studies.
Freelancers
Freelancers utilize Langfuse's prompt management and Playground features to efficiently develop and test new language model applications, optimizing their workflows and output quality.
Startups
Startups integrate Langfuse into their development processes to rapidly iterate on LLM applications, using its API and SDKs to customize and scale their solutions.
How We Rate Langfuse
Langfuse vs Competitors
Langfuse vs Warestack
Warestack is a robust competitor offering similar LLM development tools. However, Langfuse's open-source nature and comprehensive observability features provide greater flexibility and insights for debugging and optimization.
- + Open-source flexibility
- + Comprehensive observability
- + Robust security compliance
- + Extensive integration capabilities
- − May require technical expertise for setup
- − Higher pricing for enterprise features
Langfuse Frequently Asked Questions (2026)
What is Langfuse?
Langfuse is an open-source LLM engineering platform designed for collaborative debugging, analysis, and iteration of language model applications.
How much does Langfuse cost in 2026?
Langfuse offers a free Hobby plan, with Core at $29/month, Pro at $199/month, and Enterprise at $2499/month.
Is Langfuse free?
Yes, Langfuse offers a free Hobby plan suitable for hobby projects and proofs of concept.
Is Langfuse worth it in 2026?
Given its comprehensive features, security, and open-source flexibility, Langfuse is a valuable tool for LLM development in 2026.
Best Langfuse alternatives in 2026?
Alternatives include Warestack, Opsera, TraceRoot AI, Zuzia.app, and Calmo.
Langfuse vs competitors in 2026?
Langfuse stands out for its open-source nature, robust observability, and security features compared to competitors like Warestack and Opsera.
How to get started with Langfuse?
Sign up for a free account on Langfuse's website, explore the documentation, and integrate the SDKs into your applications.
What platforms does Langfuse support?
Langfuse supports integration with popular LLM libraries and frameworks, as well as Python and JavaScript/TypeScript SDKs.
Is Langfuse safe and secure?
Yes, Langfuse complies with SOC2 and ISO27001 standards, ensuring data privacy and security for its users.
Who should use Langfuse?
Langfuse is ideal for AI development teams, enterprises, research institutions, startups, and Fortune 500 companies.
What's new in Langfuse 2026?
Langfuse continues to enhance its features and security measures, maintaining its position as a leading LLM engineering platform.
How does Langfuse compare to alternatives?
Langfuse offers unique advantages such as open-source flexibility and strong security, making it a competitive choice among LLM platforms.
Langfuse Search Interest
Search interest over past 12 months (Google Trends) • Updated 2/2/2026
Langfuse on Hacker News
Langfuse Company
Langfuse Quick Info
- Pricing
- Open Source
- Upvotes
- 189
- Added
- January 3, 2026
Langfuse Is Best For
- AI Development Teams seeking collaborative debugging tools
- Enterprises requiring secure and compliant LLM platforms
- Research Institutions conducting language model experiments
- Startups looking for cost-effective LLM development solutions
- Fortune 500 Companies optimizing LLM application performance
Langfuse Integrations
Langfuse Alternatives
View all →Related to Langfuse
News & Press
ClickHouse Completes $400 Million Series D Funding and Acquires Langfuse - Global Legal Chronicle
15 AI Agent Observability Tools in 2026: AgentOps & Langfuse - AIMultiple
Inside AI Agent Watchdogs: Langfuse, AgentOps and the Race for Unbreakable Autonomy - WebProNews
ClickHouse Raises $400M Series D Led by Dragoneer to Accelerate Expansion Across Analytics and AI Infrastructure - Business Wire
Compare Tools
See how Langfuse compares to other tools
Start ComparisonOwn Langfuse?
Claim this tool to post updates, share deals, and get a verified badge.
Claim This Tool