
Helicone AI
LangSmith
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Braintrust.dev
Portkey
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Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.

Helicone AI
MarginDash
LangSmith
LLMCap
OpenAI
Corrath
Claude by Anthropic
Know your AI costs per customer, per feature, per tier. PerUnit attributes every dollar of AI provider spend to the customers and features driving it.

Which is more popular?
Based on our record, Langfuse seems to be more popular. It has been mentioned 34 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | langfuse.com | perunit.ai |
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| Company | Startup from the United States | — |
| Listed in |
In their own words, as submitted to SaaSHub.


Langfuse is an open-source LLM engineering platform designed to empower developers by providing insights into user interactions with their LLM applications. We offer tools that help developers understand usage patterns, diagnose issues, and improve application performance based on real user data....
Your AI bill is growing — but which customers, features, and pricing tiers are driving it? OpenAI, Anthropic, and Google dashboards show totals. Totals don't help you decide who to charge more, what to gate, or where to cut. PerUnit breaks down AI spend by customer, feature, and pricing tier so...
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


No analysis of Langfuse yet.
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
Langfuse in two minutes
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Langfuse and PerUnit.
PerUnit's answer:
PerUnit is built for AI unit economics, not just cost tracking. We break down AI spend by:
Customer — see which accounts drive costs Feature — see which AI features burn through tokens Pricing tier — free vs paid user breakdown We connect AI costs to revenue via Stripe. Provider dashboards show totals; observability tools show tokens. PerUnit shows who's driving costs and whether they're profitable. No data warehouse or pipelines — direct API sync to OpenAI, Anthropic, and Google.
PerUnit's answer:
PerUnit is built for product and pricing decisions, not observability. Competitors focus on tokens, latency, and traces. We focus on:
Cost per customer Cost per feature Cost per tier — connected to revenue If you need to know who to charge more, what to gate, or where to cut, PerUnit gives you that. No pipelines, no data engineering, no data warehouse.
PerUnit's answer:
Founders, product managers, and CFOs at companies building AI-powered products. Anyone who needs to answer:
Which customers cost the most? Are free users profitable? Should we gate AI behind paid plans? Teams that care about unit economics and margins, not just total spend.
PerUnit's answer:
We've shipped products with AI and watched margins disappear without knowing why. The AI bill was one number — we couldn't see which customers or features were driving it. Every product and pricing decision was a guess.
We built PerUnit so product teams can have the same clarity on AI costs that they have on revenue and headcount.
PerUnit's answer:
Frontend: Next.js, React, TypeScript, Tailwind CSS Integrations: OpenAI, Anthropic, Google APIs, Stripe Deployment: Vercel
PerUnit's answer:
PerUnit is in early access. We're onboarding a small group of teams who need clarity on their AI unit economics. Our early users are founders and PMs at companies building AI features — from early-stage to growth — who want cost attribution before scaling further.
Share your experience with using Langfuse and PerUnit. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


Ten free AI prompt tools in 2026 across four categories: prompt generators (SurePrompts, Anthropic Console, OpenAI Playground), libraries (AIPRM, PromptHero, FlowGPT, Awesome ChatGPT Prompts), open-source workflow...
We have no reviews of PerUnit yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


Langfuse is an open-source observability and analytics platform for LLM applications. Its open-source nature is a significant draw for companies that prefer to self-host or want to avoid vendor lock-in. - Source: dev.to / 1 day ago
We have researched and experimented with several AI evaluation platforms, including Arize Phoenix, Microsoft Foundry, and Langfuse. After evaluating them against our requirements and roadmap, we shortlisted Microsoft Foundry and Langfuse... - Source: dev.to / 11 days ago
Langfuse is the other serious option in this category if you also want observability, evals and traces bundled with prompt management. Different scope, more setup, worth comparing honestly. - Source: dev.to / about 1 month ago
Tracking PerUnit since Mar 2026.
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