Alternatives to W&B Weave
LLM application tracing and evaluation toolkit from Weights & Biases.
W&B Weave ranks #7 of 8 in AI evaluation platforms, with an Alt Score of 93. It is licensed under Apache-2.0, freemium from $60/month and available on the web. 13 of 13 checklist rows are verified against a public source.
Weave is the Weights & Biases toolkit for tracking, evaluating, and monitoring LLM applications, with tracing, scorers, and experiment comparison.
Developers and teams building LLM applications and agents who need to debug non-deterministic outputs, run rigorous evaluations, and monitor production behavior — from solo developers on the free tier to enterprise teams needing HIPAA-compliant, self-managed deployments. It integrates with agent SDKs and harnesses (OpenAI Agents SDK, Google ADK, Claude Code) and LLM providers/orchestration frameworks (OpenAI, Anthropic, Bedrock, LangChain, LlamaIndex, DSPy) rather than being tied to one stack.
An observability and evaluation platform: automatic tracing of agent sessions and function calls (Ops, Calls, Traces, Threads) with cost/token tracking, a no-code Playground and Evaluation Playground for testing and comparing prompts/models with LLM-as-judge scorers, versioned Datasets and Prompts, annotation queues for human review, and production monitoring via built-in Signals, custom monitors, guardrails, and automations (Slack/webhook alerts on regressions).
Developers install the open-source Weave Python or TypeScript SDK (Apache-2.0, wandb/weave on GitHub), decorate functions with @weave.op or use autopatched provider integrations, and call weave.init to stream traces to a W&B project. Evaluations, scorers, and datasets are versioned Weave objects referenced by immutable ref URIs. Weave is offered as part of the hosted W&B SaaS platform (free, Pro at $60/month, or custom Enterprise) or as a self-managed instance deployed on customer infrastructure with a ClickHouse backend.
Why people leave W&B Weave
Dashed reasons are sourced facts; the rest are opinions. Vendors can dispute.
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Ranked alternatives
Ordered by Alt Score. Click any score to see the breakdown.
Opik is an open-source LLM evaluation platform from Comet for tracing, evaluating, and monitoring LLM applications, with datasets, LLM-as-judge metrics, and a prompt playground.
Langfuse is an open-source LLM engineering platform providing tracing, prompt management, evaluations, datasets, and analytics for LLM applications; self-hostable or cloud.
Phoenix is an open-source observability and evaluation library from Arize AI for tracing, evaluating, and troubleshooting LLM applications, built on OpenTelemetry.
Braintrust is an evaluation and observability platform for AI products, with datasets, LLM-as-judge scorers, prompt playground, and production logging.
HoneyHive is an AI evaluation and observability platform for testing, tracing, and monitoring LLM applications, with datasets, LLM-as-judge evaluators, and human review.
LangSmith is a platform for debugging, testing, evaluating, and monitoring LLM applications, with tracing, datasets, and LLM-as-judge evaluations.
Feature comparison
Rows come from the AI evaluation platforms checklist (17 rows). Human-verified cells only. ? means the value has not been verified.
| AI evaluation platforms checklist | W&B Weave | Comet Opik | Langfuse | Arize Phoenix | Braintrust | HoneyHive |
|---|---|---|---|---|---|---|
| Pricing model | ||||||
| Starts at | ||||||
| License | ||||||
| Platforms | ||||||
| Open source | ||||||
| Self-hostable | ||||||
| Tracing / observability | ||||||
| Prompt playground & versioning | ||||||
| Dataset management | ||||||
| LLM-as-judge evals | ||||||
| Human annotation / review | ||||||
| Online (production) monitoring | ||||||
| A/B experiments | ||||||
| CI / regression testing | ||||||
| Cost & token tracking | ||||||
| Framework-agnostic SDK | ||||||
| Free tier |
Every fact and feature listed for W&B Weave is verified against its own pages. Each alternative is sourced on its own page.
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Pricing model Freemium verified 2026-07-17
Free Designed for personal development of AI applications and models $0/mo GET STARTED Includes AI application evaluations AI application tracing AI application scorers ... Pro Professionals working t
https://wandb.ai/site/pricing/ -
Platforms Web verified 2026-07-17
Weave is a hosted web app (wandb.ai) plus Python/TypeScript SDKs; SDKs are not part of the allowed platforms enum so only Web is recorded.
Cloud-hosted Privately-hosted
https://wandb.ai/site/pricing/ -
Status active verified 2026-07-17
Release notes list frequent point releases through April 2026; GitHub API shows the wandb/weave repo was pushed to on 2026-07-17 (the day of this research), confirming ongoing active development.
0.52.37 April 17, 2026 Added OpenTelemetry integrations follow the latest semantic conventions.
https://docs.wandb.ai/release-notes/weave-sdk-releases -
License Apache-2.0 verified 2026-07-17
Applies to the Weave SDK/client repo (wandb/weave) on GitHub, confirmed Apache-2.0 via the GitHub API license field as well. The W&B hosted platform/backend that Weave traces into is proprietary SaaS.
Apache License Version 2.0, January 2004
https://raw.githubusercontent.com/wandb/weave/master/LICENSE -
Starts at $60/month verified 2026-07-17
Pro Professionals working to optimize AI applications and models Starts at $60/month, billed monthly START YOUR 30 DAY FREE TRIAL
https://wandb.ai/site/pricing/ -
Open source Partial verified 2026-07-17
The Weave client SDK / eval library (wandb/weave, Apache-2.0) is genuinely open source, but the hosted W&B Weave observability platform and UI you compare here are proprietary SaaS — not a self-hostab
Apache License Version 2.0, January 2004
https://raw.githubusercontent.com/wandb/weave/master/LICENSE -
Self-hostable Yes verified 2026-07-17
Self-hosting W&B Weave gives you more control over its environment and configuration. This can help you create a more isolated environment and meet additional security compliance.
https://docs.wandb.ai/weave/guides/platform/weave-self-managed -
Tracing / observability Yes verified 2026-07-17
W&B Weave is an observability and evaluation platform for building reliable LLM applications.
https://docs.wandb.ai/weave/concepts/what-is-weave -
Prompt playground & versioning Yes verified 2026-07-17
Weave automatically tracks every version of your prompts, creating a complete history of how your prompts evolve.
https://docs.wandb.ai/weave/guides/core-types/prompts-version -
Dataset management Yes verified 2026-07-17
Weave datasets help you organize, collect, track, and version examples for LLM application evaluation and side-by-side comparison.
https://docs.wandb.ai/weave/guides/core-types/datasets -
LLM-as-judge evals Yes verified 2026-07-17
Compare and evaluate model performance using evaluation datasets and LLM scoring judges.
https://docs.wandb.ai/weave/guides/tools/evaluation_playground -
Human annotation / review Yes verified 2026-07-17
Annotation queues provide a focused review interface for domain experts. You review one item at a time, examine the provided context, and submit structured feedback using predefined fields.
https://docs.wandb.ai/weave/guides/tracking/annotation-review -
Online (production) monitoring Yes verified 2026-07-17
Automated scoring: Every incoming production trace is automatically processed and scored on common quality issues and errors.
https://docs.wandb.ai/weave/guides/evaluation/monitors -
A/B experiments Partial verified 2026-07-17
Weave supports side-by-side comparison of traces/prompts/models and an Evaluation Playground for comparing model variants, but no evidence was found of randomized live-traffic A/B splitting for produc
The W&B Weave Comparison feature lets you visually compare and diff code, traces, prompts, models, and model configurations. You can compare two objects side-by-side or analyze a larger set of objects
https://docs.wandb.ai/weave/guides/tools/comparison -
CI / regression testing Yes verified 2026-07-17
The pricing page also lists 'CI/CD automations' as a Pro-plan feature (https://wandb.ai/site/pricing/).
Regression detection: Send an alert when a scorer detects a drop in accuracy or an increase in toxicity.
https://docs.wandb.ai/weave/guides/evaluation/automations -
Cost & token tracking Yes verified 2026-07-17
Weave tracks the cost of LLM calls in two ways: Automatic cost tracking ... Weave captures token usage from the API response and applies built-in pricing for the model, with no extra code required.
https://docs.wandb.ai/weave/guides/tracking/costs -
Framework-agnostic SDK Yes verified 2026-07-17
Integrations page lists LLM providers (OpenAI, Anthropic, Bedrock, Cohere, Google, Groq, Hugging Face, etc.) and orchestration frameworks (LangChain, LlamaIndex, DSPy, and others); README states weave
Weave provides two ways to integrate with your AI stack ... These integrations capture individual LLM calls and pipeline steps as Weave Calls in the Traces view.
https://docs.wandb.ai/weave/guides/integrations -
Free tier Yes verified 2026-07-17
Free Designed for personal development of AI applications and models $0/mo GET STARTED Includes AI application evaluations AI application tracing AI application scorers AI model experiment tracking
https://wandb.ai/site/pricing/
FAQ
Yes. Arize Phoenix, Braintrust and HoneyHive have a free tier or are fully free. Free-tier limits in the comparison table are verified and dated.
Comet Opik, Langfuse and Arize Phoenix — every license claim links its source.