Website performance analyzer

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.

See a sample reportno signup · no card · takes one click
One click
no signup, no card, full report
Real page load
we render your site, not a guess
AI on every run
included free, never an upsell
Top 3 fixes
ranked by what they’re worth
01 — What you get

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.

app.harpoon.solutions10 FINDINGS
73
GRADE C
Render-blocking JS/CSS47
Critical path length76
Third-party overhead75
Cache quality91
FIX FIRST
P0
Defer the 19 render-blocking scripts
Gain: ~1.2 s faster first paint · Effort: medium
P1
Trim third-party scripts (7% of bytes)
Gain: 2.3 s less cumulative request time · Effort: medium
Illustrative report

One number you can defend

Five weighted dimensions, openly scored. Every point you lost points at a request — so you can argue with it, not just stare at it.

A fix list in priority order

Ranked by what it buys you, with the effort spelled out. Start at the top, stop when your page is fast enough.

Proof the fix worked

Re-run after you ship and see the delta. No more shipping a change and hoping it helped.

Analyze your site Takes one URL and about a minute.
02 — How it works

One URL in. A plan you can act on out.

STEP 01

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.

STEP 02

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.

STEP 03

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.

Try it on your homepage or read a sample report first
03 — Staying fast

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.

Scheduled re-runs on the pages that earn you money
Alerts by email, Slack or webhook when the score drops
A trend line per page, so you can see the drift before customers do
Pricing page · dailyREGRESSION
Score dropped 71 → 48 overnight
A new analytics tag added 2 render-blocking requests. Flagged the morning it shipped.
04 — What’s in each tier

The analysis is free. You pay to stop watching it yourself.

FREE
Performance and Accessibility
Separate project views and useful saved history.
FREE
Full score, findings and explanation
Deterministic results with a clear fix plan.
FREE
One daily public-page monitor
A real automatic check, plus in-app status when it succeeds or fails.
FREE
200 results per product
30-day retention and 10 hosted browser jobs each day.
PREMIUM
Authenticated capture
Record sign-in and multi-step paths behind a login.
PREMIUM
25 monitors and rich alerts
Email, Slack or webhook when a page regresses.
PREMIUM
CI/API and source-control tooling
Bring performance checks into delivery and turn findings into code changes.
PREMIUM
5,000 results per product
365-day retention, 50 hosted browser jobs each day and 5 workspace members.
Start with a free report Upgrade when you need more capacity, authenticated flows and team integrations.
05 — Pricing

Two products. Two tiers. One workspace.

Performance and Accessibility are included together. Hosted work is bounded by clear capacity limits; there are no overage charges.

Free

Useful every day, not a trial

$0forever
Start free
Performance and Accessibility project views
200 saved results per product · 30-day retention
1 daily public-page monitor
10 hosted browser jobs/day · 1 member
Unlimited local extension audits and local HAR analysis
Everything included

Premium

Every implemented paid software feature

$29/month
14-day card-up-front trial · billed monthly · cancel anytime
Review Premium

Checkout is temporarily unavailable; the displayed offer remains $29/month.

Everything in Free
Authenticated capture, monitoring, alerts, sharing and CI/API
Source-control tooling, supported SSO and manual-audit software
5,000 saved results per product · 365-day retention
25 monitors · 50 hosted browser jobs/day · 5 members

Human audit services are not included in the software subscription.

06 — Questions

The honest answers.

Anything missing? Ask us directly.

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. Anonymous results stay 7 days. New workspace results use the tier’s retention window: 30 days on Free or 365 days on Premium. You can delete them sooner.

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 included in Premium — Harpoon records the sign-in once and can then capture and re-run pages inside your app.

Find out in a minute what
you’ve been guessing at.

no signup · no card · AI explanation included