Comet ML free tier includes Comet makes Opik, for LLM and agent observability and evaluation, and an MLOps platform for ML… Verified November 2026. Compare with 8 alternatives in AI / ML.
Subtypes in AI / ML: llm_observability — records the prompts, responses, latency, cost and tool calls an application sent to a model, for reading afterwards; llm_evaluation — scores model or agent output against a dataset, a rubric or a judge model on runs you trigger; experiment_tracking — records training or evaluation runs, their metrics and artifacts, and keeps a registry of model versions. We read that on 2026-09-01 from https://www.comet.com/site/pricing/, where it says: “Track and compare machine learning training runs Dataset management and versioning Model Registry” How we use this.
Comet ML's free tier offers Comet makes Opik, for LLM and agent observability and evaluation, and an MLOps platform for ML experiment tracking… We rate it stable. One recorded limit reduction narrowed the terms, on 2026-04-14. Best for ai / ml workloads — 8 alternatives available.
Comet makes Opik, for LLM and agent observability and evaluation, and an MLOps platform for ML experiment tracking. Opik is open source and free to self-host. Opik Free Cloud allows up to 10 team members, 25k spans per month and 60-day data retention, with agent tracing and analysis, test suites and assertions, and Agent Playground. MLOps Free covers 1 platform user, with experiment tracking, dataset management and versioning, Model Registry and 100GB of data storage. Academics can apply for a free Pro plan.
We read that on 2026-11-06 from https://www.comet.com/site/pricing/, and our check recorded: the page names Comet ML as "comet ml" and states "10 team members 25k spans per month" and "100GB/month".
Free Cloud Perfect for individuals $0 Free plan Get Started Up to 10 team members 25k spans per month 60-day data retention
How Comet ML compares against every one of the 8 we list, not against a selection of them. A surface with room for every member of a tied set may rotate their order. A surface with room for only some of them names none of them, because which ones it named would be the claim, and a claim seeded on the date is not the one we serve tomorrow. How we decide this.
| Service | Free Tier | Stability |
|---|---|---|
| Comet ML | Free | stable |
| Braintrust | Free Evals, prompt playground, and data management for Gen AI. Starter plan (free): 1 GB processed data/month, 10k scores/month, 14 days data retention. |
stable |
| Keywords AI | Free Rebranded to Respan; keywordsai.co redirects to respan.ai. Free plan: full platform, 100k logs, 1k scores, 5 datasets, 2 evaluators, 5 prompts. |
source unconfirmed |
| Weights & Biases | Free ML experiment tracking, model registry, and LLM app tracing and evaluation (Weave). W&B's hosted service is now sold as CoreWeave Forge. |
stable |
| Langfuse | Free Open-source LLM engineering platform for tracing, evaluating and debugging AI applications. The Langfuse Cloud Hobby plan is free with no credit card: 50k units a month (each trace, observation and score counts as one unit), 30 days of data access, 2 users, community support via GitHub, and all… |
stable |
| Arize AX | Free Platform for agent observability, evaluation and improvement. AX Free costs $0 with no credit card required: 25k trace spans per month, 1 GB ingestion per month, 15 days of retention, unlimited users and evals, 10 Signal issues per month, the Alyx agent and community support. |
unrated |
| LangSmith | Free LLM observability and evaluation platform by LangChain — Developer plan is $0/seat/month with up to 5k base traces/month, then pay-as-you-go. LCU is $1.50/unit and LSU is $1.00/unit. |
unrated — change unconfirmed |
| LangWatch | Free A LLMOps platform helping AI teams measure, monitor, and optimize LLM applications for reliability, cost-efficiency, and performance. With a powerful DSPy component, we enable seamless collaboration between engineers and non-technical teams to fine-tune and productionize GenAI products. |
unrated |
| Portkey | Free Control panel for Gen AI apps featuring an observability suite & an AI gateway. Send & log up to 10,000 requests for free every month. |
unrated |
Left out of this list: Hugging Face (shares no subtype with this product), Groq (shares no subtype with this product), Google Gemini API (shares no subtype with this product), Mistral AI (shares no subtype with this product), OpenRouter (shares no subtype with this product), Cloudflare Workers AI (shares no subtype with this product), Cerebras (shares no subtype with this product), Cohere (shares no subtype with this product), Brave Search API (shares no subtype with this product), OpenAI (shares no subtype with this product), Pinecone (shares no subtype with this product), Qdrant (shares no subtype with this product), Deepgram (shares no subtype with this product), Kaggle (shares no subtype with this product), Roboflow (shares no subtype with this product), Scale AI (shares no subtype with this product), AssemblyAI (shares no subtype with this product), Replicate (shares no subtype with this product), Baseten (shares no subtype with this product), Clarifai (we have not classified this record), Neptune.ai (we have not classified this record), Labelbox (shares no subtype with this product), Google Colab (shares no subtype with this product), Composio (shares no subtype with this product), DeepAR (none of this category's subtypes apply), Maxim AI (shares no subtype with this product), OCR.Space (shares no subtype with this product), Parseur (shares no subtype with this product), Reducto (shares no subtype with this product), SerpApi (shares no subtype with this product), Tavily AI (shares no subtype with this product), paperspace (shares no subtype with this product), Audio Enhancer (none of this category's subtypes apply), Clair (none of this category's subtypes apply), Langtrace (we have not classified this record), Lumenfall.ai (shares no subtype with this product), Mediaworkbench.ai (none of this category's subtypes apply), Othor AI (none of this category's subtypes apply), Pollinations.AI (shares no subtype with this product), ReportGPT (none of this category's subtypes apply), Zenable (none of this category's subtypes apply), xAI (shares no subtype with this product), Anthropic API (shares no subtype with this product), GitHub Models (shares no subtype with this product), NVIDIA NIM (shares no subtype with this product), Ollama Cloud (shares no subtype with this product), LLM7.io (shares no subtype with this product), SiliconFlow (shares no subtype with this product), Zhipu AI (shares no subtype with this product), DeepSeek API (shares no subtype with this product), MiniMax (shares no subtype with this product), Exa (shares no subtype with this product), GPU-Bridge (we have not classified this record), Google Vertex AI Agent Engine (we have not classified this record), Google Vector Search 2.0 (shares no subtype with this product), Google Gemini Embedding 2 (shares no subtype with this product), Alibaba Cloud Qwen Code (none of this category's subtypes apply), E2B (shares no subtype with this product), Together AI (shares no subtype with this product), Fireworks AI (shares no subtype with this product), Modal (shares no subtype with this product), ElevenLabs (we have not classified this record), Stability AI (we have not classified this record), Daytona (shares no subtype with this product), Blaxel (shares no subtype with this product), Novita Sandbox (shares no subtype with this product), Runloop (shares no subtype with this product), Mem0 (shares no subtype with this product), Zep (shares no subtype with this product), Letta (we have not classified this record), Supermemory (shares no subtype with this product), Cognee (shares no subtype with this product), Serper (shares no subtype with this product), Linkup (shares no subtype with this product), Parallel (shares no subtype with this product), Jina AI (shares no subtype with this product), You.com (shares no subtype with this product), Hetzner Inference API (shares no subtype with this product), Cloudflare AI Search (we have not classified this record), Valyu (shares no subtype with this product). Each is still listed in AI / ML, with the vendor's own words we read that from on its page. How we decide this.
We do not push notifications. Every change we record is readable the moment it lands, and the JSON answer carries an ETag — send it back as If-None-Match and an unchanged answer costs one 304.
curl https://agentdeals.dev/api/changes?vendor=Comet%20ML
curl https://agentdeals.dev/pricing-changes/feed.xml?vendor=Comet%20ML