Arize AI
ML and LLM observability with drift detection, tracing and automated evaluation.
why this verdict
Keep paying — OpenAI has not replaced it
OpenAI's version overlaps, but does not finish the dev tools job, so this one still earns its $50/mo.
- A named launch, not a vibe named, unlinked
- LLM observability startups and model providers offering evaluation tooling for free. OpenAI, August 5, 2025 — no announcement link recorded yet.
- How much of the job it covers not the job editorial call
- Parts of it. The job still needs the tool to get finished.
- Is there a free way to do it? yes
- 1 of 3 listed replacements have a usable free tier: Langfuse.
- What the call is worth $600/yr
- $50/mo at the entry paid tier — $600 a year per seat.
- Threatened by
- OpenAI
- Since
- August 5, 2025
- List price
- $50/mo
- Per year
- $600
The backstory
Arize started in classic ML observability, catching drift and degradation in production models, and moved early into LLM tracing with the open-source Phoenix project. Free tooling from every direction compresses the low end. It survives because enterprises deploying agents need evidence, not vibes, about how those agents behave in production, and Arize is one of the few vendors with the monitoring rigour from the pre-LLM era plus an open-source on-ramp that gets it into teams cheaply.
Escape hatches
Open-source LLM observability, simpler to adopt
langfuse.com open_in_newStronger evaluation and experimentation workflow
braintrust.dev open_in_newPrivacy-preserving monitoring for data and models
whylabs.ai open_in_new1 of 3 replacements have a usable free tier.
