LangSmith vs Helicone in 2026 - Neither Is the Obvious Answer

People pit LangSmith against Helicone because they sit at opposite ends of the observability market. LangSmith is the turnkey, deeply-integrated, closed platform from the LangChain team. Helicone was the light, open, cheap proxy you reached for to avoid exactly that kind of lock-in and bill. It was the classic “open alternative to the expensive incumbent” matchup. Here is the problem with running it in 2026: one of these is expensive and locked-in, and the other is frozen. LangSmith’s trace bill explodes at scale and you cannot self-host your way out below Enterprise. Helicone went into maintenance mode after Mintlify bought it. So this comparison has an honest third answer, and I have put Langfuse in the table for that reason.

The short version

Tool	Best for	Pricing at scale	Self-host / license
LangSmith	LangChain and LangGraph apps	~$2,514/mo at 1M traces	Enterprise only, closed
Helicone	Nobody new - maintenance mode	$79/mo Pro, overage unpublished	Free, Apache-2.0, but frozen
Langfuse	The all-round open-source default	~$101/mo at 1M events	Free, MIT, near-complete

LangSmith: the best LangChain experience, at a price

LangSmith is the most turnkey observability you can point at a LangChain app. Add a callback and every chain, tool call and agent step shows up traced with zero extra work. Nothing touches it for depth on LangChain and LangGraph code, because nobody else ships LangChain. The eval side is strong too - Align Evals, its workflow for calibrating an LLM judge against human scores, is genuinely useful. It is backed by a well-funded company; LangChain, Inc. raised roughly $260M at a $1.25B valuation, so survival is not the question.

The question is cost and lock-in. Base traces are $2.50 per 1,000 at 14-day retention, extended traces $5.00 per 1,000, and at 1M base traces on one seat that works out to roughly $2,514/mo - about 25x what Langfuse costs. And you cannot self-host your way out: LangSmith is fully closed source, and self-hosting is Enterprise-only behind a sales call. It accepts OpenTelemetry as a receiver, so you are not forced onto the LangChain SDK, but the zero-config magic only shows up when you use it. If you live in LangChain and the bill does not scare you, stay. Otherwise the alternatives are cheaper.

Helicone: clean proxy, frozen future

I will give Helicone its due. It was the lightest-weight of the major observability tools - a logging proxy first. You change your API base URL to route through it, and it logs everything with zero SDK, in any language, against any provider. That was genuinely faster to wire up than instrumenting your code, and it is Apache-2.0 and self-hosts free. By the time Mintlify bought it, it had processed 14.2 trillion tokens across roughly 16,000 organizations. There is also an async SDK logging mode for when you do not want the proxy in your critical path.

Two gotchas. The first is structural: the proxy sits in the hot path of every LLM call, a single point of failure - if Helicone is down your calls fail even when the provider is healthy, and each proxied call adds latency, which Helicone cites at around 10ms. The second is decisive: Helicone is in maintenance mode since the 3 March 2026 Mintlify acquisition - security patches, bug fixes and new-model support only, no roadmap, and Mintlify is helping customers migrate off. For a new build that overrides everything. The exact overage above 10k requests is not even published, so you could not forecast the Pro bill anyway. If you are already on it, use the runway to plan your exit. The Helicone page has the detail.

Langfuse: the answer this comparison keeps pointing to

Here is the tool that solves both problems at once. Langfuse gives you LangSmith’s cost problem in reverse and Helicone’s openness without the freeze. It is MIT-licensed and self-hosts free with only three features enterprise-gated, it is framework-agnostic, and it runs about $101/mo at 1M events versus LangSmith’s roughly $2,514/mo - the widely-cited ~25x gap. It does tracing, evals, prompt management and human annotation, and it is actively developed, not winding down. When LangChain cut its old free tier, Reddit threads pushed a visible wave of users toward self-hosted Langfuse for exactly these reasons.

Its honest catch is operational: v3 needs Postgres plus ClickHouse, Redis and S3-compatible storage - four services - and the migration is where self-hosters get stuck. It is also a ClickHouse subsidiary now after the January 2026 acquisition. If you cannot spare the ops capacity, the $29/mo Core cloud tier sidesteps the whole thing and still beats LangSmith badly at scale.

LangSmith vs Helicone: which should you pick?

• You are all-in on LangChain and LangGraph and the bill does not scare you - LangSmith. The zero-config tracing really is the deepest for that stack, and Align Evals is a real reason to be there.
• You are cost-sensitive at production volume - not LangSmith. The trace bill and Enterprise-only self-host leave no cheap way out. Go Langfuse.
• You wanted Helicone’s open, low-friction proxy - understand it is frozen. Get the openness and the cost advantage from Langfuse instead, which is still shipping.
• You are evaluating fresh and want the safe default - Langfuse. Open-source, framework-agnostic, and roughly 25x cheaper than LangSmith at scale.
• You are already on Helicone - plan your migration. Do not build anything new on it.

This is a comparison where the honest recommendation is often the third tool. LangSmith is the right pick for one specific team - the one that lives in LangChain and can absorb the bill. Helicone is the right pick for nobody new. For everyone in between, Langfuse is the tool this whole comparison keeps pointing at. Every price and date here was read from each vendor’s own materials, verified on 26 July 2026, and this category ships breaking changes monthly, so we re-verify every 30 days.