FloatCheck

Safe floating-point comparison for developers. Stop using === on floats.

Value A

Value B

Epsilon

API Access

Pro

$5/mo

Unlimited API calls, authentication tokens, JSON responses

✓ REST API with API key auth
✓ Epsilon & ULP comparison modes
✓ Batch comparison endpoint
✓ Priority support

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FAQ

Why not use === for floats?

Floating-point arithmetic is inexact. 0.1 + 0.2 === 0.3 is false in every language. Epsilon comparison checks if two values are close enough within a tolerance.

What epsilon should I use?

For general use, 1e-9 works well. For financial calculations use a domain-specific tolerance. For scientific computing, consider relative epsilon based on the magnitude of your values.

How does the API work?

Send a POST to /api/compare with Authorization: Bearer YOUR_KEY and a JSON body with a, b, and optional epsilon. Returns equal, diff, and epsilon used.