Generated fast. Verified before ship.

Paste an artifact your assistant produced. DevTools works out what it is and hands it to a deterministic verifier that catches the almost-right output before it reaches production. Detection and verification both run in your browser — nothing is uploaded.

Try:

Or choose a verifier

What each verifier proves

Every check below is deterministic: it either holds or it does not. Anything inferred rather than proven is labelled HEURISTIC in the results.

JSON: Shape drift against the response you expected — missing keys, type mismatches, null surprises.
JWT: Expiry, not-before, alg:none, issuer and audience mismatches, and HMAC signatures when you supply the secret.
Cron: The next eight runs in a named timezone, daylight-saving gaps and repeated hours.
Unified diff: File and hunk structure, plus clearly-labelled review suggestions for changed conditionals and removed guards.
URL: Double encoding, duplicate parameters, credentials in the authority, and redirect_uri mismatches.
YAML: Duplicate keys, tab indentation, the Norway problem, and constructs that do not survive JSON conversion.
SQL: Clause outline, table and alias map, DELETE/UPDATE without WHERE, and joins with no condition.
CSV: Ragged rows, duplicate headers, BOM bytes, delimiter detection and inferred column types.
.env: Keys the example declares but your local file lacks, duplicates, and credentials committed to .env.example.
Regex: Labelled test cases with false positives and false negatives called out by name.
Timestamps: Every timestamp in a log line, rendered in the timezone you choose.

Common problems, worked through

Each one shows a real failing input and the verdict the verifier gives it.

Will my cron job skip or run twice on daylight saving?A daily cron at 02:30 does not run at all on the spring-forward date in most US and European zones, and runs twice in autumn. Check any expression against a named timezone.The API returned a string where my code expects a numberAn id that arrives as "1042" instead of 1042 passes every smoke test and breaks a client. Compare the response shape you expect against the one you received, by exact path.Why is my JWT rejected?Decode a JSON Web Token in your browser and see exactly which claim fails: expired, not yet valid, unsigned, or issued for a different audience. Nothing is uploaded.Which environment variables am I missing?Compare your local .env against .env.example and the keys your deployment actually has. Find what is missing, what is extra, and what should never have been committed.

What it does not do

It does not call a language model. Detection and every verifier are pure functions over your input.
It does not prove your code is correct. A patch that parses cleanly can still be wrong.
It does not execute anything. SQL is read, never run; cURL commands are parsed, never shelled out.
It does not put credentials in a share link. Secret fields are excluded from every URL, on every path.

Read more in the verification workflow docs, or see how local processing works.