See what’s slowing
your site down.
Paste a URL. Harpoon loads your page for real and tells you, in plain English, what to fix first.
Not a wall of metrics.
A shortlist of decisions.
You don’t need another dashboard to interpret. You need to know which three things to change this week, and what each one is worth.
One URL in. A plan you can act on out.
You paste a URL
We open your page in a real browser and record the whole load, exactly as a visitor gets it. Nothing to install.
The engine ranks what’s slow
Rules, not vibes. The same page load always produces the same findings and the same score — and each one names the request behind it.
You get it in plain English
The AI explains the findings the engine already made: what to change, why it matters, what it’s worth. It never sees your raw capture.
Fast once is luck.
Fast in six months is a system.
Sites get slow one harmless-looking script at a time. Put your key pages on a schedule and Harpoon re-runs them for you, keeps the history, and tells you the day something regresses.
The analysis is free. You pay to stop watching it yourself.
Free to find out. Paid to stay fast.
Drop-in
Answer one question, today
Patrol
Never wonder if it’s still fast
Fleet
Signed-in pages and whole teams
Do I need to sign up to get a report?
No. Paste a URL and you get the score, every finding, and the plain-English explanation — no account, no card. An account is only for keeping reports, watching pages on a schedule and building history.
Is the AI explanation really free?
Yes, on every report, signed in or not. The engine finds the problems on its own; the AI’s job is only to explain findings that already exist — which is also why it can’t invent numbers.
What do you actually send to the AI model?
Only the structured findings and page metadata the engine produced — no request or response bodies, headers, or cookies. Credentials, cookies and response bodies are stripped before anything is stored.
How long do you keep my data?
Your capture is deleted as soon as we’ve analyzed it — usually within seconds. We keep only what we derived from it: the findings, score and request timeline. Those stay 7 days if you ran anonymously, or until you delete them with an account. We don’t claim anything stays on your device — the analysis runs on our servers.
Is this the same as a Lighthouse score?
No. It’s our own weighted score across five dimensions of the real network load, and every point lost traces to a specific request. Same page load in, same score out.
What if my page is behind a login?
That’s the Fleet plan — Harpoon records the sign-in once and can then capture and re-run pages inside your app.