Free local tool

Edge-Case Catalog

Filter documented LLM edge-case classes by category, copy reproduction prompts, and preserve explanations for controlled Claude tests.

llm edge caseswhy can't llms count lettersClaude edge case examples

Key facts

Cite facts
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Fact

Filterable catalog

Search by category, difficulty, or keyword to find a focused fixture for an experiment.

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Fact

Copyable prompts

Each card includes a benign reproduction prompt you can copy into a controlled test run.

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Fact

Explanations, not dunking

The catalog frames edge cases as fixture design material, not proof that a model always fails.

Filterable fixture catalog

Find a benign edge case to test

Use these prompts as fixtures inside a documented protocol. A single surprising answer is not a benchmark result.

How to Use This Tool

  1. Choose a category. Filter by tokenization, counting, spatial reasoning, grounding, instruction conflict, or format control.
  2. Copy a benign prompt. Use the prompt as one fixture in a larger test, not as a one-off benchmark claim.
  3. Record the result. Save the model ID, date, prompt, raw output, scoring note, and whether the behavior reproduces.

Tool FAQ

Are these guaranteed Claude failures?

No. They are edge-case classes worth testing. A current Claude model may pass, fail, or ask for clarification depending on prompt, model, and surface.

Why include toy prompts?

Toy prompts make the failure class visible before you test production-like fixtures. They should not replace realistic task evaluation.

Can I add risky jailbreak prompts?

No. The catalog is limited to benign edge cases. Safety-boundary testing belongs in controlled, non-operational protocols.

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