Helicone

Helicone is an open-source LLM observability platform and AI gateway that adds traces, cost tracking, caching and prompt management to any OpenAI-compatible app with a single base-URL change. We rate it 82/100 — the fastest on-ramp in the category for teams that want production-grade LLM monitoring without giving up self-hosting or vendor neutrality, provided you can live with a UI that still trails Langfuse on depth and a free tier that is noticeably tighter than the open-source competition.

What is Helicone?

Helicone is built by Justin Torre and Cole Gottdank, co-founders who went through Y Combinator's W23 batch and first shipped the platform in March 2023. The company's pitch is to give developers "Datadog for LLMs" — a control plane that sits between your app and whatever model provider you use, logs every request, and surfaces cost, latency and quality metrics without requiring you to redesign your code.

As of April 2026 the open-source repo at github.com/Helicone/helicone has 5,500+ stars, ships under the Apache-2.0 license, and runs on TypeScript with Cloudflare Workers, ClickHouse and Kafka under the hood. The company says its gateway has now processed over 2 billion LLM interactions, and the v2025.08.21 release line added a proper development lifecycle — log, evaluate, experiment, review, release — that moved Helicone from "a nice logger" to something closer to LangSmith's scope.

Key Features of Helicone

• One-line integration: Swap your base URL from api.openai.com to oai.helicone.ai (or the equivalent Anthropic, Gemini or OpenRouter proxy) and you are logging. No SDK wrappers, no decorators, no code rewrites — Helicone's distributed proxy adds on average 50–80ms of latency.
• AI Gateway for 100+ models: A single OpenAI-compatible endpoint that routes to OpenAI, Anthropic, Google, Mistral, Groq, DeepSeek, Together, Fireworks and OpenRouter, with intelligent fallback and provider-level load balancing.
• Built-in caching that actually saves money: Response caching on exact and semantic matches typically cuts API spend by 20–40% on production workloads, per Helicone's own customer data — a feature LangSmith still does not offer.
• Prompt management and experiments: Version prompts in a UI, push new versions through the gateway with zero redeploys, and run regression tests against historical production traffic using LLM-as-judge or custom Python evaluators.
• Traces, sessions and agent observability: Multi-step agent runs, tool calls, vector DB lookups and embedding calls are stitched into a single tree — useful for debugging why a LangGraph or LiteLLM pipeline went off the rails.
• Real open source, real self-host: Apache-2.0 licensed with a supported Helm chart, so teams with data-residency or HIPAA requirements can run the full stack on their own infrastructure.

What Users Say About Helicone

On Product Hunt, Helicone holds a 5.0 average across 13 reviews and cleared 166 upvotes at launch, with reviewers repeatedly calling out the "works out of the box" setup and the concrete savings from caching. On Hacker News, the v2 Show HN thread (42806254) drew mostly positive reactions from YC peers and independent builders, with the common refrain being that the one-line proxy is the thing that got them to try it instead of LangSmith.

Complaints are real. On Reddit's r/LocalLLaMA and r/LangChain, the recurring knock is that Helicone's evaluation and dataset tooling is still less mature than Langfuse or LangSmith — good enough for basic regressions, not yet good enough for serious eval suites. A few engineers also note that the 10k request/month free tier is generous for hobby projects but disappears fast in production, pushing teams onto the $79 Pro plan sooner than they expected.

Helicone Pricing

Helicone uses a freemium model with usage-based overages above each tier's included allowance. Self-hosting the open-source build is always free.

Plan	Price	Key Limits
Hobby	$0/month	10k requests, 1GB storage, 7-day retention, 10 logs/min, 1 seat
Pro	$79/month	10k free + usage-based, unlimited seats, alerts, HQL, 1-month retention
Team	$799/month	5 orgs, SOC-2 & HIPAA, dedicated Slack, 3-month retention, 15k logs/min
Enterprise	Custom	SAML SSO, on-prem, forever retention, 30k logs/min, custom MSA

Who Should Use Helicone?

Best for: solo builders and small engineering teams shipping LLM features who want proper observability, cost tracking and caching without a LangChain-style framework lock-in. Especially useful for teams already using OpenRouter or multi-provider setups where a single gateway is the point.

Not ideal for: companies that need the deepest eval tooling in the category (pick Langfuse or LangSmith), or teams whose compliance posture rules out proxying traffic through a third-party gateway at all — in which case the self-hosted Helm chart is the only viable option.

Pros and Cons

Pros:

• True one-line setup — measured in minutes, not hours, on real Product Hunt reviews.
• Caching that materially reduces spend, a feature LangSmith does not have.
• Permissive Apache-2.0 license with a supported self-host path.
• Provider-agnostic: not tied to LangChain, LlamaIndex, or any single framework.

Cons:

• 10k-request free tier is tight compared to Langfuse Cloud's more generous free limits.
• Evaluation tooling is still less mature than Langfuse and LangSmith.
• 50–80ms proxy overhead, while small, matters for latency-critical agent loops.
• Pro-tier jump to $79/month can feel steep for side projects that just outgrow the free limit.

Alternatives to Helicone

Langfuse is the other serious open-source option, with stronger evals and a simpler single-Postgres architecture, but no built-in caching. LangSmith is the most polished commercial product and the default if you are already deep in LangChain, but it is proprietary and has no caching layer. Braintrust is the heavyweight choice for eval-first teams, at a correspondingly higher price point.

Verdict: Is Helicone Worth It?

Yes — for most teams shipping LLM features in 2026, Helicone is the right default. It gets you 80% of what LangSmith offers at roughly a third of the friction, ships the cost controls and caching LangSmith does not, and keeps a credible self-host story that Langfuse fans will also appreciate. We rate it 82/100: very good, with a couple of real rough edges around evals and free-tier limits that keep it out of the 90s for now.

Frequently Asked Questions

Is Helicone free?

Yes. Helicone has a free Hobby plan that includes 10,000 requests per month, 1GB of storage and 7-day retention — enough for side projects and prototypes. Paid plans start at $79/month for Pro. The open-source self-hosted build is always free under Apache-2.0.

Is Helicone open source?

Yes. The full platform is open source under the Apache-2.0 license at github.com/Helicone/helicone, with an official Helm chart for self-hosting on Kubernetes.

How does Helicone compare to Langfuse?

Helicone is faster to integrate (one base-URL change versus an SDK) and includes built-in caching that can cut API spend 20–40%. Langfuse has deeper evaluation tooling and a more generous free tier on its cloud offering. For multi-provider gateways and cost optimization, Helicone wins; for serious eval workflows, Langfuse is still ahead.

What platforms does Helicone support?

Helicone runs as a web dashboard plus an OpenAI-compatible HTTP gateway, so any language or framework that can call a REST API can use it — Node.js, Python, Go, Rust, Ruby and the full set of LLM SDKs all work without code changes.

Does Helicone support Anthropic, Gemini and open-source models?

Yes. The AI Gateway routes to 100+ models across OpenAI, Anthropic, Google, Mistral, Groq, DeepSeek, Together, Fireworks, OpenRouter and any OpenAI-compatible endpoint, with automatic fallback between providers.