CAPTCHA: Math

Solve a server-rendered arithmetic captcha (digits drawn as SVG, not text)

What you will learn

Read a value that is rendered as pixels/SVG strokes, not as queryable DOM text
Understand practice mode (answer leaked) vs hard mode (answer server-only → needs OCR/solver)
Submit and assert a server-issued verdict, never a client-side success flag

Math CAPTCHA — Solve the Sum

Two digits are drawn as 7-segment SVG strokes (not text) and the sum is sealed inside an HMAC token — reading the operands needs OCR, not a DOM query

Each operand is rendered server-side as a distorted 7-segment glyph made of SVG <line> elements, so the actual numbers never appear as selectable or queryable text anywhere in the DOM. Add them up and type the result.

Mode: practice — the answer is leaked below so a naive test can pass.

Solve & Answer

What is the sum of the two numbers?

Testing Tips

Automation hints

✓ The operands are SVG <line> strokes, not text — there is no innerText/value to read; page.getByText() will never find the digits
✓ In ?mode=practice the sum is leaked in #captcha-answer-hint — parse it for a naive pass; in ?mode=hard decode the data:image/svg+xml from each <img> and OCR the 7-segment glyphs (or call a solver)
✓ Type the sum into #captcha-answer and click #captcha-submit; use #captcha-reload for a fresh pair (tokens expire ~5 min)
✓ The verdict is computed server-side at POST /api/captcha/verify (403 on a wrong sum) — you cannot fake it from the client
✓ Assert success on #captcha-result[data-verdict=human], not just any result message

Related Challenges

CAPTCHA: Math

Solve a server-rendered arithmetic captcha (digits drawn as SVG, not text)

What you will learn

Read a value that is rendered as pixels/SVG strokes, not as queryable DOM text
Understand practice mode (answer leaked) vs hard mode (answer server-only → needs OCR/solver)
Submit and assert a server-issued verdict, never a client-side success flag

Math CAPTCHA — Solve the Sum

Two digits are drawn as 7-segment SVG strokes (not text) and the sum is sealed inside an HMAC token — reading the operands needs OCR, not a DOM query

Mode: practice — the answer is leaked below so a naive test can pass.

Solve & Answer

What is the sum of the two numbers?

Testing Tips

Automation hints

✓ The operands are SVG <line> strokes, not text — there is no innerText/value to read; page.getByText() will never find the digits
✓ In ?mode=practice the sum is leaked in #captcha-answer-hint — parse it for a naive pass; in ?mode=hard decode the data:image/svg+xml from each <img> and OCR the 7-segment glyphs (or call a solver)
✓ Type the sum into #captcha-answer and click #captcha-submit; use #captcha-reload for a fresh pair (tokens expire ~5 min)
✓ The verdict is computed server-side at POST /api/captcha/verify (403 on a wrong sum) — you cannot fake it from the client
✓ Assert success on #captcha-result[data-verdict=human], not just any result message

Related Challenges

IndexedDB Basics

Medium

Rich Text Editor

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Trace Forensics

Medium

CAPTCHA: Math

What you will learn

Math CAPTCHA — Solve the Sum

Solve & Answer

Testing Tips

Timer

Need Help?

Related Challenges

IndexedDB Basics

Rich Text Editor

Trace Forensics

CAPTCHA: Math

What you will learn

Math CAPTCHA — Solve the Sum

Solve & Answer

Testing Tips

Timer

Need Help?

Related Challenges

IndexedDB Basics

Rich Text Editor

Trace Forensics