Spanlens alternatives
Spanlens is a proxy-based tool for tracking the cost, latency, tokens and traces of LLM calls, with evaluations, alerts, PII masking and self-hosting. When choosing a replacement, first decide whether you need observability alone or also a routing gateway, pre-release simulation, or enterprise governance. Then check self-hosting, pricing model and whether agent tracing and evaluations matter for your workload.
Comparing with
Open-source LLM observability: log cost, latency, tokens
Quick picks
- LangSmithEmpower Your LLM Applications with LangSmith
- LangfuseOpen-source observability and analytics for LLM applications
- LangWatchEnhance GenAI Solutions with User Analytics
All 15 alternatives
Ranked by how well each one does what Spanlens does.
- 1LangSmithSame job
Empower Your LLM Applications with LangSmith
Claim this listingPick it if you need step-by-step agent run views, online evaluations and alerts, and want a hosted, self-hosted or bring-your-own-cloud option.
Drop-in replacementFreeSimilar price to SpanlensView LangSmith - 2LangfuseSame job
Open-source observability and analytics for LLM applications
Claim this listingPick it if you want open-source tracing with prompt versioning, one-click rollback, and self-hosting via container or infrastructure templates.
Covers most of itFreemiumSimilar price to SpanlensView Langfuse - 3LangWatch
Enhance GenAI Solutions with User Analytics
Claim this listingPick it if you want multi-turn agent simulation and red-team tests before release, and your budget covers a paid tool.
Covers most of itFreemiumCosts more than SpanlensView LangWatch - 4
Comet.comStreamline your machine learning model lifecycle with Comet
Claim this listingPick it if you also run ML experiment tracking and a model registry, and want LLM traces in the same platform.
Covers most of itFreeSimilar price to SpanlensView Comet.com - 5
AgentopsEnhance AI Agent Performance with Analytics
Claim this listingPick it if you mainly need to debug agent runs with event visualization and time-travel replay, using a pip-installable Python SDK.
Covers most of itFreeSimilar price to SpanlensView Agentops - 6
PortkeyEasily productionize AI apps with Portkey's AI Gateway & observability features.
Claim this listingPick it if you need one API across many LLM providers with fallbacks, load balancing and budget limits, not mainly observability.
Covers most of itFreeSimilar price to SpanlensView Portkey - 7
Confident AIComprehensive LLM Evaluation Platform
Claim this listingPick it if your priority is evaluation-led quality work, such as gating releases in CI on eval results and curating datasets with human annotation.
Covers most of itFreeSimilar price to SpanlensView Confident AI - 8
Future AGIAutomate QA for AI Models with Future AGI's Smart Critique Agents
Claim this listingPick it if you need real-time guardrails against prompt injection and PII leaks alongside agent simulation, with Docker self-hosting.
Covers most of itFreemiumSimilar price to SpanlensView Future AGI - 9
BraintrustBuild High-Quality AI Products with Confidence
Claim this listingPick it if you turn production traces into regression datasets and need natural-language trace search, SSO and RBAC, and can pay for it.
Covers most of itPaidCosts more than SpanlensView Braintrust - 10
PromptLayerBoost AI productivity with prompt engineering
Claim this listingPick it if non-technical domain experts need to edit prompts in a visual editor, and you want a free pricing model.
Covers most of itFreeSimilar price to SpanlensView PromptLayer - 11
BerriAICustomize ChatGPT Apps with BerriAI
Claim this listingPick it if you need an open-source gateway with virtual keys, per-team budgets, and self-hosting in private or air-gapped environments.
Covers most of itFreeSimilar price to SpanlensView BerriAI - 12
Monitor MLReal-time ML model monitoring made simple
Claim this listingPick it if you monitor classical ML models and LLM agents together in a web-based tool with production performance alerting.
Covers most of itFreeSimilar price to SpanlensView Monitor ML - 13
OrquestaStreamline LLM operations with a no-code integration platform
Claim this listingPick it if your organization needs policy controls, approvals and audit trails over LLM and coding agent traffic, and can pay for it.
Covers most of itPaidCosts more than SpanlensView Orquesta - 14
Eden AIYour one-stop hub for top-tier AI APIs!
Claim this listingPick it if you need EU-only endpoints and one OpenAI-compatible API over many models, with per-key budgets and allow-lists, on a paid plan.
Covers most of itFreemiumCosts more than SpanlensView Eden AI - 15
UltraAIOptimize Language Learning Machine (LLM) operations with AI command center
Claim this listingPick it if you want a low-cost option centered on semantic caching, model fallbacks and per-user rate limits.
Covers most of itFreeCosts less than SpanlensView UltraAI
Spanlens and its top 5, side by side
| What we compared | | LangSmith | Langfuse | LangWatch | Comet.com | Agentops |
|---|---|---|---|---|---|---|
| What it does | Open-source LLM observability: log cost, latency, tokens | Empower Your LLM Applications with LangSmith | Open-source observability and analytics for LLM applications | Enhance GenAI Solutions with User Analytics | Streamline your machine learning model lifecycle with Comet | Enhance AI Agent Performance with Analytics |
| Fit for Spanlens users | — | Drop-in | Covers most | Covers most | Covers most | Covers most |
| Pricing | Freemium | Free | Freemium | Freemium | Free | Free |
| Free plan | Yes | Yes | Yes | No | Yes | Yes |
| API | Yes | Yes | Yes | Yes | No | No |
| Open source | Yes | No | Yes | Yes | Yes | No |
| Platforms | Web, CLI, API | Web, API | Web, API, CLI | Web, API, CLI | Web, API | Web |
Questions about Spanlens alternatives
What are the best alternatives to Spanlens?
On AINave, the closest matches are LangSmith, Langfuse and LangWatch.
Is there a free alternative to Spanlens?
Yes. 11 alternatives have a free plan, including LangSmith, Langfuse and Comet.com.
Which Spanlens alternatives have an API?
10 alternatives have an API, including LangSmith, Langfuse and LangWatch.
Is there an open-source alternative to Spanlens?
Yes. 5 alternatives are open source, including Langfuse, LangWatch and Comet.com.
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