What is the main difference between LangWatch and Spanlens?

LangWatch and Spanlens are both llm observability & evaluation but differ in their approach, features, and target audience. Compare their GitHub stats, technology stack, and community adoption to make the best choice.

Which is better: LangWatch or Spanlens?

The choice between LangWatch and Spanlens depends on your specific needs, technical requirements, and team preferences. Both are quality open source solutions with active communities.

Can I migrate from LangWatch to Spanlens?

Migration between LangWatch and Spanlens is possible but requires careful planning. Consider data export/import capabilities, feature parity, and potential workflow changes.

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LangWatch vs Spanlens

Learn how LangWatch and Spanlens differ in their key features, development activity, technology stack and community adoption, so you can decide which of these llm observability & evaluation is best for you.

LangWatch

Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence.

Visit LangWatch Read more

4,765stars+1,275(+37%)

Last 30 days

Last commit
9 hours ago
Repository age
3 years
Version
v1.2.0
License
Apache-2.0
Repository
langwatch/langwatch

Spanlens

Drop-in observability platform for OpenAI, Anthropic, and Gemini that logs every request, tracks costs, traces agent workflows, and flags anomalies and PII.

Visit Spanlens Read more

13stars

Last 30 days

Last commit
7 days ago
Repository age
5 months
License
MIT
Self-hosted
Yes
Repository
spanlens/spanlens

Detailed Comparison

Both LangWatch and Spanlens have their unique strengths and serve similar purposes effectively. Consider your specific needs regarding popularity, activity, technology, maturity, licensing and features when making your decision.

LangWatch wins

Community & Popularity

LangWatch significantly outpaces Spanlens in community adoption with 4,765 stars compared to 13 stars on GitHub. This 366.5x difference suggests LangWatch has a much larger and more active community. In terms of developer contributions, LangWatch has 384 forks, indicating moderate developer engagement.

Comparable

Development Activity

Both projects show recent activity, with LangWatch last updated 9 hours ago and Spanlens 7 days ago.

Comparable

Technology Stack

Both tools share common technology foundations, being built with JavaScript, CSS, Bash, Typescript, JSX, Python. However, they differ in their additional technology choices: LangWatch uses SCSS, Golang, Ruby while Spanlens leverages Next.js.

LangWatch wins

Project Maturity

LangWatch has been in development longer, starting 3 years ago, compared to Spanlens which began 5 months ago. This 2.7-year head start suggests LangWatch may have more mature features and established processes.

Spanlens wins

Licensing

Spanlens uses the MIT license, which is more permissive than LangWatch's Apache-2.0 license, potentially offering greater flexibility for commercial use and integration.

Comparable

Use Cases & Features

Both tools serve similar use cases in LLM Observability & Evaluation.

Spanlens wins

Hosting & Deployment

Spanlens provides self-hosting options for complete data control and customization, while LangWatch may be primarily cloud-based or require different deployment approaches.