Comparison
13x vs Lighthouse
What Lighthouse and PageSpeed Insights is good at
Measuring rendering. Lighthouse runs a real browser, traces the load, and gives you Core Web Vitals with a waterfall behind them. Nothing here replaces it for diagnosing why a specific page paints slowly — and it is free, from Google, and already in your browser.
Tools of this kind include Lighthouse, PageSpeed Insights and Chrome DevTools audits. This page compares the category rather than any one product, because what a named tool does changes and a table that is wrong about somebody else’s product is worse than no table.
Where the overlap ends
It scores one URL at a time in a simulated environment, and its remit is the page. It does not know whether your sitemap is declared, whether GPTBot receives a 403, whether your DMARC record has a policy, or whether analytics fires before consent — because none of those are questions about rendering.
Side by side
Where do the performance numbers come from?
- Lighthouse and PageSpeed Insights
- A real headless browser with simulated throttling. Lab data, with a full trace.
- 13x
- Causes read from the response: what is render-blocking, uncompressed, undeclared, unsized. No simulated score.
How many pages?
- Lighthouse and PageSpeed Insights
- One URL per run.
- 13x
- A crawl of your product, with per-page findings rolled up.
Does it check AI crawler access?
- Lighthouse and PageSpeed Insights
- No. Out of remit.
- 13x
- Yes — robots.txt per agent, plus the status each agent actually receives.
Does it check email deliverability?
- Lighthouse and PageSpeed Insights
- No.
- 13x
- SPF, DKIM, DMARC and MX from DNS.
Does it check consent ordering?
- Lighthouse and PageSpeed Insights
- No.
- 13x
- Whether a tracker fires before consent, and whether the legal pages exist and resolve.
Is the result stable between runs?
- Lighthouse and PageSpeed Insights
- Scores move between runs on the same page — the lab is simulated, and that is expected.
- 13x
- Deterministic. The same response produces the same finding every time, which is why it can be diffed across deploys.
Every claim in the 13x column is checkable against the public rule registry, which lists all 113 rules with their weights and scope.
When not to switch
If your question is why the largest contentful paint on one page is 4.2 seconds, open Lighthouse. It has the trace and we do not. Use 13x for the surfaces around it, and for the fact that they keep changing after you fix them.
See what it finds on your product
113 checks against your live URL, in about 30 seconds. No account. Every failing check comes back with its evidence and the fix for the framework we detect.
No signup. Results in 30 seconds.