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Oh Dear

The client forwards a 54

Lighthouse SEO monitoring.

The client forwards a PageSpeed score of 54. Your last Lighthouse run was a DevTools tab after the previous deploy. Oh Dear runs Google Lighthouse against your sites every day, keeps the full reports, and notifies you when a score or metric crosses the threshold you set.

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Capterra
4.9 (73) G2
4.7 (33)
Daily by default Six months of reports
  • Bitmovin
  • HBO Nordic
  • Obsidian
  • Laravel
  • Fathom Analytics
  • PHP 8
  • Stanford University
  • Takeaway.com
  • IGN
  • VRT NWS
  • spatie

Up is not fast

Uptime stays green while scores sink.

An uptime check asks the server a question and grades the answer. A Lighthouse check renders the page the way a visitor's browser does, then grades what it finds. Both matter, and they fail independently.

Same deploy, two verdicts Illustrative values

Uptime check

Status
200 OK
Response
272 ms
Sees
The HTTP response. Nothing rendered.
Verdict
Up

Lighthouse check

Performance score
95, now 78
Largest Contentful Paint
1.8 s, now 4.6 s
Sees
The rendered page, weighed and timed
Verdict
Over the 4,000 ms threshold

A 23 MB image uploaded to the CMS does this overnight. Server timings are a third signal: performance monitoring times every request, every minute.

What one run produces

Four scores. Six metrics. One report.

Each run loads the page in a browser, applies the Lighthouse audits, and stores the full report. You get the scores, the lab metrics behind them, and recommendations with the estimated savings attached.

Scores from 0 to 100

Performance How fast the page loads and how well it uses its resources.
Accessibility Contrast, alt text, labels and the other checks that help people using assistive tech.
Best practices HTTPS, console errors, deprecated APIs and other signs of a page built with care.
SEO Titles, meta descriptions, crawlable links and the basics search engines look for.

Lab metrics

Paint timings First Contentful Paint, Largest Contentful Paint and Speed Index.
Interactivity Time to Interactive and Total Blocking Time.
Stability Cumulative Layout Shift: how much the page jumps around while it loads.

The full report

Every audit The complete Lighthouse report, readable inside Oh Dear, run by run.
Priced fixes Recommendations show the estimated saving, so the 2 MB image gets fixed before the font that saves a few kilobytes.
Through the API List reports, or fetch the latest one, to build your own dashboards.

History, not a snapshot

Pinpoint the day scores moved.

A single score tells you where you stand. History tells you what changed, when, and whether your fix worked. That is evidence you can forward to the client.

shop.example performance Illustrative
  1. Steady for three weeks. 95
  2. Deploy 4.2.1 ships an oversized hero image. 78
  3. Images resized. The next run confirms the fix. 91

When performance drops from 95 to 78, the trend shows the exact day, so you can match it against deploys, content updates and third-party scripts. Gradual decline shows up too: scores rarely collapse overnight, they sag as a site grows. Oh Dear keeps every run for six months, with trend graphs for the scores and the metrics.

Nicolas Lefèvre
Started using Oh Dear as a simple monitoring tool. It has become a daily must-have for uptime, performance and page speed metrics audits.

Nicolas Lefèvre, Technical Consultant

Page speed audits are only useful if somebody runs them. This check runs them for you, every day.

Thresholds you set

Decide what counts as a regression.

Every score and every metric has its own threshold, and each one can be switched off. These are the defaults a new site starts with.

Default thresholds.

  • Each of the four scores. Below 50
  • First Contentful Paint. Over 3,000 ms
  • Speed Index, Largest Contentful Paint, Time to Interactive. Over 4,000 ms
  • Total Blocking Time. Over 600 ms
  • Cumulative Layout Shift. Over 0.25
  • Before we notify you. Two runs in a row

Quiet on a blip, loud on a trend.

One slow run is often just a busy server. That is why, by default, a threshold has to be crossed in two runs in a row before we notify you. Set it to one for a faster signal, or higher for a calmer one.

Raise the bar for a site that should score in the 90s, or switch off the metrics you do not care about. When the scores come back within your thresholds, you get a recovery notification, so the channel tells you when the problem is over too.

Planned work on the site? Snooze the check until it is done.

Operational ownership

Send the slow page to the person who owns the fix.

A heavy product page on client A is not the same person's problem as a missing alt text on client B. Oh Dear routes each site's Lighthouse alerts to the people and channels that team already uses: email, Slack, Teams, Discord, SMS, webhooks and more.

The monthly client report can include a Lighthouse section, for the people who never open a dashboard.

Slack
Email
Webhook
Explore notifications and routing

One lab run, one page

What this check sees, and what it does not.

Lighthouse grades the rendered page. The neighboring checks answer different questions, and none of them can promise a ranking.

What it checks

  • Performance, accessibility, best practices and SEO scores for the monitored URL.
  • Six lab metrics, each with its own threshold.
  • The full Lighthouse report with every audit and recommendation.
  • Six months of runs, with trend graphs for scores and metrics.
  • One URL per monitor, as desktop or mobile, from Europe, North America or Asia.

What it does not

A better Lighthouse score is a better technical foundation. It is not a promise of better rankings or more traffic.

No feature tiers

Every check.
Every plan.

Lighthouse SEO monitoring is included on every plan. You pay for the number of sites you monitor, not for which checks you need.

Start with everything on.

Try Lighthouse monitoring alongside uptime, performance, broken links and the rest of Oh Dear's website checks.

  • Lighthouse checks on every plan
  • Every monitoring feature included
  • Plans scale by monitored site count
  • No credit card required
Start a free trial

10-day free trial. No credit card.

For the technically curious

How the Lighthouse check actually works.

Oh Dear sends the URL of your monitor to one of its Lighthouse servers, stores the result, and compares it against your thresholds.

  • Frequency. Once a day by default. You can slow it down to every two, three, four or five days. It does not run more often than daily.
  • Location. Lighthouse servers in Frankfurt, New York and Singapore. You pick the continent per site; by default it follows your uptime check location.
  • Device emulation. Desktop by default. Mobile simulates a slow 4G connection and a CPU four times slower, so mobile scores are usually lower.
  • Request headers. Add custom headers to the Lighthouse request, for example to get past a firewall or to tag the traffic in your logs.
  • Thresholds. A minimum score per category and a maximum value per metric, each with its own on/off switch, plus how many runs in a row must cross a threshold before we notify you.
  • Notifications. A Lighthouse issues notification when a threshold is crossed, and a recovery notification when the scores are back. Both go to the channels you configured for the site.
  • History. Reports are kept for six months. Each one holds the scores, the six metrics and the full Lighthouse report.
  • API. List the Lighthouse reports of a monitor, fetch the latest one, or fetch a single report by its ID.

Want all the technical details?

Lighthouse SEO monitoring Device emulation

Before the first check

Questions about Lighthouse monitoring.

What the lab run measures, how often it runs, and where this check ends.

What is Lighthouse SEO monitoring?

Oh Dear runs Google Lighthouse against the URL of your monitor, once a day by default. Each run gives you a 0 to 100 score for performance, accessibility, best practices and SEO, six lab metrics, and the full Lighthouse report with its recommendations. When a score or metric crosses the threshold you set, we notify you.

Does Oh Dear run Google Lighthouse audits on a schedule?

Yes. The check runs once a day by default. You can slow it down to every two, three, four or five days per site. It never runs more often than once a day: a Lighthouse run loads and audits the whole page, which is a lot heavier than an uptime request.

What does Oh Dear's Lighthouse monitoring score?

The four Lighthouse categories: performance, accessibility, best practices and SEO, each scored out of 100. Next to the scores we store six lab metrics: First Contentful Paint, Speed Index, Largest Contentful Paint, Time to Interactive, Total Blocking Time and Cumulative Layout Shift. That way you can watch the metric that moved, not just the headline number.

Will Oh Dear alert me when a Lighthouse score drops?

Yes. Set a minimum score for each category and a maximum for each metric. By default a score alerts below 50, and a threshold has to be crossed in two runs in a row before we notify you, so a one-off blip stays quiet. When the scores recover, we send a recovery notification too.

How is this different from running Lighthouse myself in Chrome?

Running Lighthouse in Chrome DevTools gives you a snapshot the moment you click. Oh Dear runs it for you on a schedule, keeps six months of history so you can see the trend, and tells you when a deploy lowers a score, without anybody having to remember to check.

How is this different from PageSpeed Insights?

A PageSpeed Insights run gives you a result for today, on demand. Oh Dear schedules the runs, stores the reports, graphs the trend and notifies you based on your thresholds. It is the same Lighthouse engine; the difference is the recurring record and the alert.

How is this different from performance monitoring?

Performance monitoring times the HTTP request every minute: DNS, connection, TLS, server time and download. It tells you whether your server answers fast. Lighthouse tells you whether the rendered page is fast, accessible and well built. Use both: the timings catch a slow server today, Lighthouse catches a heavy page this week.

Will this improve my search rankings?

Not on its own. Lighthouse measures a technical foundation you can monitor and improve: speed, accessibility and SEO basics. Rankings also depend on content, competition and links, so no score can promise rankings or traffic.

Why did my score change when nothing changed?

Lighthouse lab scores move between runs. The performance score in particular depends on how fast your server answered and on the network during that run. Watch the trend, and use the "times in a row" setting so a single dip does not alert anyone.

Does it check desktop or mobile?

Each monitor runs one device setting: desktop, the default, or mobile. Mobile simulates a slower network and CPU, so its scores are usually lower. Need both? Add the site twice with a different device setting.

Which pages does the check run on?

The URL of the monitor. Lighthouse audits one page per run, so if your product page or checkout matters as much as the home page, add that URL as its own monitor.

Where does the Lighthouse check run from?

From a Lighthouse server in Europe, North America or Asia. You pick the continent per site; by default it follows the location of your uptime check.

How long are Lighthouse reports kept?

Six months. Every run in that window keeps its scores, its metrics and the full report, and the trend graphs cover the same six months.

Is Lighthouse monitoring included on every plan?

Yes. Every feature is on every plan. You pay for the number of sites you monitor, not for turning this check on.

See all other FAQ items
Technical detail Read the Lighthouse monitoring documentation A different check Watch the server timings

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Capterra
4.9 (73) G2
4.7 (33)
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