FiscaLLM vs Langfuse

Both help you see what AI costs per user. The difference is what they compare it with, what they cost, and where your data lives. Checked on 2026-11-02 from Langfuse's public page; we make FiscaLLM, so tell us if anything about Langfuse is out of date.

	FiscaLLM	Langfuse
What it is	AI cost per user joined to real revenue: margin per user, plan and free trial	Open-source LLM observability: traces, evals, prompt management and cost tracking
Price	Free. Hosted with fair use (100,000 events per app per month), or self-hosted with no limit	Free self-hosted; hosted plans with a free tier
Hosting	Hosted or self-hosted	Hosted or self-hosted
Open source	Yes, MIT (server, dashboard and SDKs)	Yes
Revenue used for margin	Real revenue from RevenueCat (one-click connect and import), Stripe (webhook and 12-month import, beta, USD), CSV upload, or a revenue API	Tracks cost per user ID, but does not import subscription revenue to compute margin

Where Langfuse is strong

Full traces of prompts and responses for debugging
Evals and prompt management
Large community

Pick Langfuse if you need tracing, evals and prompt debugging. Many teams use it alongside FiscaLLM, which adds revenue and margin.

Why teams pick FiscaLLM

Free and open source. MIT, with the server, dashboard and SDKs in one repository. No per-event or per-seat price.
Self-hostable. Run it on your own Vercel and Postgres so revenue and usage data never leave your infrastructure.
Real revenue, from where you bill. One-click RevenueCat for App Store and Google Play apps, Stripe with 12 months of history, CSV upload, or a revenue API.
Margin per user, plan and free trial, with alerts when a paying user starts losing you money, and optional per-user caps.
Never sees prompts. Only user IDs, model names and token counts. Reporting never blocks or slows your app.

Open the demo dashboard (sample data, no sign-up), read the docs, or start free. All comparisons: AI cost per user tools compared.

Questions

Is FiscaLLM a free Langfuse alternative?

Yes. FiscaLLM is free and open source (MIT): use the hosted service at fiscallm.com or run your own copy. Langfuse: Free self-hosted; hosted plans with a free tier.

Can I use FiscaLLM and Langfuse together?

Yes. FiscaLLM only needs one tracking call after each AI request and a revenue source, so it runs next to other tools.