One measure per list
Every ranking compares one clearly defined measure. “Fastest cars” ranks recorded top speed, not acceleration; “Fastest mammals” ranks peak running speed over a short burst. The definition sits beside each list in the “How we measure” box, along with the rules for what counts.
Sources, in order of trust
- Governing bodies that ratify records, such as the FIA, World Athletics and Guinness World Records.
- Peer-reviewed studies and certified timing systems.
- Independent tests by established publications with published methods.
- Manufacturer and owner claims, which we include and label as claims.
Every figure links to its source, and we keep an archived copy where one exists.
Five labels for certainty
Each figure carries one label, shown as a color and an icon so it reads without relying on color alone.
- Official
- Ratified by a governing body such as the FIA, World Athletics or Guinness World Records.
- Verified
- Independently measured and published, for example in a peer-reviewed study or with certified timing.
- Claimed
- Stated by a manufacturer, owner or publication without independent timing.
- Estimated
- Calculated or approximated rather than directly timed.
- Disputed
- Contested by experts or contradicted by other evidence.
Picking the ranked figure
Many things have more than one published speed. An entry page lists all of them, claimed and verified, each with its source. The ranking uses one: an editor can choose it explicitly; otherwise we take the strongest label, and among equally strong figures, the best value.
Units, rounding and ties
We store each figure in the unit its source published, with the source’s precision. Conversions to km/h, mph and m/s are rounded for reading; the published unit is never rounded. Entries with the same figure share a rank and are listed alphabetically.
Records and ratification
Record histories draw the main line through ratified holdings only. Unofficial, disputed and revoked runs are shown beside the line and labeled, so the full story is visible without muddying who held the record.
Research and sign-off
Nothing is published until the figure has been checked against its source and the check has been dated. That date is kept with each source citation on the entry page.
When a page reaches search
A ranking is listed in search engines once it has at least ten verified entries. Comparison pages wait for an approved written explanation. Until then, pages are readable but marked so search engines skip them.
Corrections
Every page has a “Report an error” button, and every report is read by a person. When a figure changes, the page shows the new check date. You can also reach us through the contact page.