How we know
Methodology
Every claim on this site can be checked, so here is the whole pipeline in plain words: how a question gets written, how it gets verified, and what happens when we get one wrong.
Our own words
Written fresh, never copied
Questions written in our own words from the California Vehicle Code and the official handbook. The handbook's own wording is licensed for non-commercial use, so we never reuse it: facts and laws are free for everyone, exact wording is not. A machine check fails the build if any question overlaps the handbook text for more than a few words in a row.
Verified twice
Two independent verification passes
Every question was checked twice, by independent verifiers working from the handbook text alone, never from the writer's notes. Each pass had to agree the answer is right, every wrong choice is clearly wrong, and both passes had to pin the same PDF page. One objection from either pass killed the question. Killed questions were deleted, not patched.
01 Verification funnel
| Stage | Questions |
|---|---|
| Written | 407 |
| Killed: copied the handbook's wording | -25 |
| Killed: ambiguous or two defensible answers | -6 |
| Killed: factually wrong against the text | -2 |
| Killed: explanation claim beyond the cited page (2026-07-16 sample audit) | -1 |
| Shipped | 373 |
Machine checks
Checks that run before every change
No change ships until automated checks pass. They confirm that every question has all its fields, exactly one correct answer, and a complete citation carrying the exact revision marker (DL 600 REV. 6/2025); that no question copies the handbook's wording; and that every sign image matches its checksum in the public manifest. On top of that, at least 351 automated browser checks test the site itself, and that minimum is only allowed to grow.
A person, too
California's extra hand-check
For California, the founder also compared samples against the handbook PDF by hand before launch. That extra check is specific to California and is not what keeps this site accurate: that job belongs to the two verification passes, the independent pre-launch audit, and the machine checks. A person still reviews and deploys every release; nothing publishes itself.
The citation
What a citation contains
Every question carries three things: the handbook section it comes from, the PDF page number in the official file, and the document's own revision marker. Where a state's manual prints no marker anywhere (New York's prints none), the citation carries the agency's form identity and we publish the exact file's SHA-256 fingerprint instead, so you can verify byte for byte that you hold the same document. That is enough for you to open the official handbook and read the rule yourself. Here is a real one, from the question on our landing page:
02 Specimen citation
Laws and Rules of the Road
PDF page 42
DL 600 REV. 6/2025
Verified against the current official CA Driver's Handbook (DL 600, rev. 6/2025), checked July 2026.
Check it yourself: open the official handbook, then go to PDF page 42.
The pass lines
Why our mock exam passes at 38 of 46 and 30 of 36
- The 80 percent passing requirement is official DMV policy (dmv.ca.gov, checked July 2026). Source
- The DMV no longer publishes exact question counts or pass lines. The 46-question (pass at 38) and 36-question (pass at 30) formats used here are what recent California test-takers consistently report.
- Those reported lines are stricter than a rounded 80 percent. We apply the stricter line on purpose: if you pass here, you were not graded easier than the real test.
When we're wrong
What happens when we find an error
The question is corrected or removed, whichever the handbook supports, and the correction goes on record, dated, in the public changelog. Deleting a doubtful question always beats defending it.
New states
How a state gets added
Before a single question of a new state appears here, the current official driver handbook or manual is fetched from that state's own agency, and its source URL, edition marker when the document prints one, and checksum are recorded in a source manifest. When a manual prints no edition or revision marker at all, as New York's does not, we pin the exact served file by its SHA-256 fingerprint and publish that fingerprint, with the full dossier in the source manifest. Contradictions in the agency's own record are written down exactly as found, never smoothed over: the NY DMV's manual page describes its download as 80 pages while the link serves an 84-page file, so the fingerprinted file itself, not the page's description of it, is what every New York citation points into. Then the pipeline runs:
Every question is written in our own words from the state's laws and official manual, then verified by two independent review passes that must each pin it to the exact page of the official manual. Before launch, a third independent audit re-checks a random sample of every state's questions page by page against the official PDF. Automated checks guard every claim on this site before any change ships. When we find an error, it goes on the public corrections log, dated.
Each state's test facts (question count, pass line, retest rules) also carry a provenance label: either official, published by that state's agency, with the URL, or as reported by recent test-takers when the agency does not publish the number. Facts never copy across states.
Sources
- 1. California Driver's Handbook (DL 600 REV. 6/2025), California DMV. The document every citation on this site points into.
- 2. Instruction permits, California DMV. The official 80 percent passing requirement. Checked July 10, 2026.
- 3. Standard Highway Signs, 2024 Edition (Release 3), Federal Highway Administration. The official public-domain vector files behind every sign image. Retrieved July 10, 2026.