> ## Documentation Index
> Fetch the complete documentation index at: https://docs.weflayr.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Evaluators
> The checks that decide whether a model's answer is as good as your current one.
An evaluator judges each answer of a [benchmark](/product/model-benchmarks) against the baseline's: better, same or worse. Your library keeps them to reuse across benchmarks.
## Types
* **AI judge**: a model reads both answers and follows your instructions, e.g. "The answer names the policy clause it relies on".
* **Deterministic**: a Python check, e.g. at most 120 words. Describe it and **Generate code** writes it for you.
* **Built-in**: ready-made judges (Overall quality, Context fidelity, Instruction fidelity, Completeness, Tone fidelity).
## Test before you save
**Test on a real call** runs the evaluator on one of your calls, with your production answer and another model's, so you can check its verdict before using it in a benchmark.
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