Reproducing a composite
Take the subscores from any product page, multiply each by its board's weight from the tables above, divide the sum by one hundred and round to two decimals. That is the index. A coding agent has nine subscores to multiply, a full-stack app builder has ten. There is no other step, and no step where a figure from one board enters the other board's sum. A worked example is published in the lab notes.
Reproducing a timing
Start a monotonic clock when the prompt is submitted. For a full-stack app builder, stop it on the first 200 response from the deployed URL. For a coding agent, stop it on the agent's returned diff or completion signal for that prompt, since most coding agents never produce a hosted URL. Do not read the timer the product displays, because those timers differ in what they include. Queue time counts, cold start counts where it applies, and if the product reports completion while the deployed URL is not serving, the clock keeps running. Repeat the full nine prompt sequence five times from an empty project, then compute p10, median and p90 by linear interpolation over all 45 executions, regardless of outcome. Multiply the median by nine and divide by sixty for the derived full specification minutes figure; do not present that figure as a separately measured one.
Reproducing a pass or fail
Each prompt has one published pass criterion. Check it against the artifact and the diff, not the chat transcript. Score 100 for a clean pass, 50 where part of the criterion is met or one clarifying instruction was needed, and 0 otherwise. Two reviewers score independently, blind to which product produced the artifact, and a full band disagreement goes to a third. An execution running past 20 minutes goes to manual review rather than an automatic fail, and the outcome the reviewer records is the one that stands.
Reproducing the SEO and GEO figures
Fetch the generated public marketing page with scripts disabled, strip tags, count the bytes of remaining text and record that as the no JavaScript HTML weight. Measure LCP and CLS on a throttled connection with a cold cache. Check for a title, meta description, canonical link, robots policy, sitemap and any structured data present in the first response.
The data behind it
Every figure on this site is downloadable. Rankings for both boards and the sourced LLM reference table are at /api/rankings.json and /data/rankings.csv, and every individual execution for a currently published product is at /api/runs.json. All three carry an explicit CC-BY-4.0 licence field, so you may republish them with attribution to LLM Tier.
Conflicts and funding
No product can pay to be measured, re measured, promoted or removed, on either board. There are no sponsored rows, no paid placements and no affiliate links in any index table. The lab is funded by data licensing and consulting on measurement design, never by the products it measures. Every row is produced by the same harness on its board's own specification, so no product receives different treatment from any other product on its board.
Corrections
Send evidence through the contact form. If a measurement is wrong we correct it, mark the correction on the product page and keep the original value in the record. Where the rule was wrong rather than the data, as with the 20 minute reliability rule above, we correct the rule and leave the recorded row standing. Three corrections have been issued since the index launched, most recently the rule text above.