Ragas vs TruLens
Pick Ragas if you want dataset-level RAG metrics in a plain Python call (`evaluate` over a dataset), including non-LLM string metrics, and you accept that releases have slowed (last on 13 Jan 2026).
Pick TruLens if you want evals tied to traces of your app (it records each call and scores it), with a local dashboard, OpenTelemetry tracing and recent releases (2.16.0 on 19 Oct 2026).
How we rank: We don't pick a winner: the verdict says when each option fits, based on the sourced facts in the table. Every entry gets the same fields, taken from vendor pricing pages, docs and official repositories on the checked date, with a source link; anything we couldn't confirm says “not verified”. Commission and sponsorship don't affect order or what we say. We show no star ratings or user scores. How we review
The facts side by side
| Ragas | TruLens | |
|---|---|---|
| Open source or hosted | Open-source Python library [source, checked 2026-11-01] | Open-source Python library with a local dashboard [source, checked 2026-11-01] |
| Self-host | Runs in your own Python process; there is no server to host [source, checked 2026-11-01] | Runs in your process; it logs to a local SQLite file or a database you choose [source, checked 2026-11-01] |
| Licence | Apache-2.0 [source, checked 2026-11-01] | MIT [source, checked 2026-11-01] |
| Owner | The GitHub organisation vibrantlabsai, which hosts the repo [source, checked 2026-11-01] | Snowflake. It agreed in May 2024 to acquire TruEra, which built TruLens; the repo is still under github.com/truera [source, checked 2026-11-01] |
| Price (checked 1 Nov 2026) | Free; no pricing page [source, checked 2026-11-01] | Free; no pricing page [source, checked 2026-11-01] |
| Latest release (1 Nov 2026) | v0.4.3, 13 Jan 2026. Last push to the repo was on 24 Feb 2026 [source, checked 2026-11-01] | trulens 2.16.0, 19 Oct 2026. Last push to the repo was on 31 Oct 2026 (UTC) [source, checked 2026-11-01] |
| Integrations | LangChain and LlamaIndex wrappers; any LLM through its llm_factory [source, checked 2026-11-01] | LangChain, LangGraph and LlamaIndex apps; plain Python via TruApp; OpenTelemetry tracing [source, checked 2026-11-01] |
Release activity
- 1 Nov 2026: Ragas: the GitHub API shows v0.4.3 (13 Jan 2026) as the latest release and a last push on 24 Feb 2026. [source, checked 2026-11-01]
- 1 Nov 2026: TruLens: the GitHub API shows 2.16.0 (19 Oct 2026) as the latest release and a last push on 31 Oct 2026 (UTC). [source, checked 2026-11-01]
What we ran ourselves (2026-11-01)
Same 5-question dataset in both. The app returns fixed answers (4 right, 1 wrong on purpose), so no model is called and nothing is paid for. Ragas used its built-in non-LLM metrics. TruLens used a custom Python feedback function that checks whether the reference answer appears in the output, recorded with TruBasicApp to a local SQLite file.
| Ragas | TruLens | |
|---|---|---|
| Version tested | ragas 0.4.3 | trulens 2.16.0 (trulens-core) |
| Metric | StringPresence; NonLLMStringSimilarity | Custom feedback: reference contained in output |
| Scores (5 rows) | StringPresence 1, 1, 0, 1, 1. NonLLMStringSimilarity 0.161, 0.05, 0.238, 0.262, 0.086 | 1, 1, 0, 1, 1 |
| Install notes | With a fresh install, `import ragas` failed until we pinned langchain-community below 0.4. String similarity also needs rapidfuzz | Installed and ran without changes |
Not tested:
- LLM-judged metrics (faithfulness, context relevance, groundedness): they need a paid model call, and we kept this test free.
- The TruLens dashboard UI, and anything in Snowflake.
- Speed or cost at scale.
Where a vendor's own comparison favours itself
| Claim | Who says it | How to read it |
|---|---|---|
| TruLens context relevance ranks ahead of Ragas | trulens.org homepage, citing AIMultiple (23 Mar 2026) [source, checked 2026-11-01] | This is a third-party benchmark, but TruLens chose to quote it on its own homepage. Check the benchmark's date and setup before relying on it. |
FAQ
Who owns TruLens?
TruLens was built by TruEra. Snowflake agreed in May 2024 to acquire the TruEra AI Observability platform, and TruLens remains open source under MIT.
Is Ragas still maintained?
On 1 Nov 2026, its latest release was v0.4.3 (13 Jan 2026), and the repo was last pushed on 24 Feb 2026. Check the repo before you adopt it.
Do I need an API key?
Not for the deterministic metrics we ran. LLM-judged metrics in either library need a model provider key.
Can I use both?
Yes. Both are Python libraries and do not conflict. Ragas needed a langchain-community pin in our install.