Performance is a product story, but only if you can prove it on the devices your customers carry. Redline gives you a shareable score, a plain-language verdict, and the evidence to back your speed claims — without buying a device lab.
Score this device“We're fast on a flagship” is easy. “We score a B on the cheapest phone in our market” is defensible. Redline gives you a number tied to the device your customers actually own.
Point Redline at any URL and it audits the delivery path — document weight, blocking scripts, third-party origins — so you can compare apples to apples without a paid tool.
Each run produces a verdict, a cohort description and concrete fixes. Send the link in a sprint review or a sales deck instead of a wall of Chrome DevTools tabs.
If the index tanks on a mid-tier Android, that's the segment bouncing before the page even paints. Redline names the cohort so product can prioritise the fix.