About OnTimeIndex
Reliability, from the federal record.
OnTimeIndex started with a question that turns out to be surprisingly hard to answer: of the two flights on the same route at roughly the same price, which one is actually more likely to get there on time? The U.S. government has published the answer every month for decades — carriers are required to file it — but it lives in raw monthly datasets with millions of rows, not in anything a traveller can read.
So Eric built the layer that was missing. OnTimeIndex turns the Bureau of Transportation Statistics' on-time performance filings into free, no-account tools that score airlines and routes on how reliably they run — and show, on every page, exactly which filings the score was computed from.
Eric builds and maintains OnTimeIndex, writes its methodology pages, and runs the monthly job that pulls new BTS filings in. He isn't a pilot, an airline analyst, or an industry insider — and this site is deliberately built so that doesn't matter. Nothing here rests on his judgement about an airline; it rests on federal filings that anyone can download and check, reduced by arithmetic that every tool page spells out.
Part of the Veraino network of free tool sites.
How it works
Every tool on OnTimeIndex is grounded in a documented, citable method — a published formula, an authoritative standard, or a well-established model. We don't approximate or invent numbers. If we can't cite a primary source for the logic, we don't publish the tool.
For this site, exactly one class of source qualifies as authoritative: the on-time performance data U.S. carriers are required to file with the Department of Transportation, published by the Bureau of Transportation Statistics. We don't blend in flight-tracker feeds, airline press releases, or third-party estimates, and we don't forecast — every number describes flights that have already happened and is reproducible from the public dataset.
Before a tool ships, its arithmetic is checked against the raw filings for a known sample, and the page states which months of data it covers. Where the federal definitions do the work — a flight is “on time” if it reaches the gate less than 15 minutes after its scheduled arrival — we use them unchanged rather than inventing our own thresholds.
Our commitments
- Free, no sign-up required. Every tool on this site is free to use with no account, subscription, or paywall.
- We show our work. Every tool explains its methodology, cites its sources, and surfaces assumptions — so you can verify the logic, not just trust the output.
- Honest about limitations. Where precision is limited or assumptions are required, we say so. Tools compute; they don't replace professional judgment.
- Kept current. Tools that use figures that can change over time carry a “last reviewed” date and are treated as an ongoing maintenance responsibility, not a one-time build.
Get in touch
Questions, corrections, or suggestions: hello@ontimeindex.com. Eric reads every message personally.