What happens when the math model is unsure
2026-03-11 · Arithmetic captchas
If the math model cannot parse a sum, the text reader tries the same image and the answer is not marked reliable.
math: true selects the arithmetic model. When that model reads a sum, engine is math and reliable follows the usual rule. Type text only in that case.
When the math model reads nothing it can parse, the service tries the text reader limited to digits and operators. If that parses, engine is ocr and reliable stays false, so you are not charged. Treat it as a miss. Refresh the portal image.
Do not flip the same bytes to numeric: true and submit whatever digits come back. A code is not the sum, and that second call can be a charged text read of the wrong problem.
One image, one option set, one submit.
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