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Looptail as a Braintrust alternative
Braintrust is the eval-first platform — the best-funded company in this category, and deservedly respected for its experimentation workflow. Here's an honest comparison for teams deciding what they actually need.
Where Braintrust wins
If your team's center of gravity is before production — building datasets, running experiments, comparing prompts and models side by side — Braintrust is excellent. The experiment UI is polished, scorer tooling is deep, and an $80M Series B means resources to keep shipping. As an experimentation IDE for AI teams, it earns its reputation, and we won't pretend otherwise.
Where Looptail is different
Looptail lives where Braintrust's workflow hands off: production, and the questions production raises. What did the system decide at 2:14pm? Who approved the prompt change that followed? Can you prove either to someone who doesn't trust your dashboard? Every Looptail record is append-only, signed, and linked — decision toevaluation to change — and the whole loop (replay, canary,approval gates) writes that evidence as a by-product. Against Braintrust we are the audit-and-automation layer, not the experimentation IDE.
| Braintrust | Looptail | |
|---|---|---|
| Experimentation | Best-in-class: datasets, experiments, playgrounds, diffs | Not the focus; replay against regression sets serves the loop |
| Evals | Eval-first product, strong scorer tooling and UI | Continuous rubric evaluators on recorded and live traffic |
| Pre-production workflow | A genuine strength — built for iterating before you ship | Assumes production traffic; built for what happens after |
| Automated improvement | Insights and workflow; human executes changes | Patch proposals, replay, canary, approval gates |
| Signed audit trail | No — logs and experiments in mutable stores | Append-only, hash-chained, Ed25519-signed; CLI-verifiable |
| Compliance evidence export | Manual, via APIs | Dated, self-verifying evidence packs; EU AI Act-oriented |
| Funding & maturity | $80M Series B (Feb 2026); best-funded in category | Early, small, focused on the evidence layer |
| Price of entry | Free tier; paid plans scale with usage | Free tier: 10k loop events/mo, 30-day retention, export |
Comparison reflects public information as of July 2026. Spot an error?Tell us and we'll fix it.
The two-tool answer
These products are less substitutes than stages. Iterate in an experimentation tool if that workflow fits you; once decisions ship, give them a record that stands on its own — signed, exportable, verifiable by a third party withone CLI command. Teams facing theEU AI Act's record-keeping obligations will need that layer regardless of which experimentation tool they love.