Introducing our public tools section: try Oh Dear! without an account

We launched a cool new feature that everyone can enjoy: public versions of all the checks available within Oh Dear!

Now you can try Oh Dear! without even creating an account.

The philosophy behind our public checks #

Why give something away for free if others are paying for it?

We love creating tools and features that are useful for everyone, not just our paying customers. We figured there's value in offering one-off checks on our site without devalueing our offer to our paying customers.

It's a perfect way to try us out without the extra hassle of creating an account, even if it only takes 5 seconds to start a trial.

Public Checks - Introduction

The public checks have their limitations:

  • They are one-off checks, they don't run every minute
  • There are no notification options to alert you, other than the browser window
  • There's no API to automate checks

But, let's focus on the good news!

Availability tool #

Want to know if a particular site is available worldwide? You can now test using our availability checker which will test from 5 different locations spread across all continents.

Public Checks - Uptime

Try out the availability checker at

Down for everyone or just me? #

Many of us know and perhaps use the site to check if a site is online worldwide. Well, we can now be an alternative for that.

To help users quickly identify problems, there's now a Chrome extension you can use to check the availability of the site you're currently on.

Alternatively, you can create a new bookmark with the following URL and you it as a bookmarklet. Oldskool, right? :-)


This snippet, when used, can allow you to quickly test any website. If you're on a site that doesn't load for you, hit that bookmarklet or the Oh Dear! browser extension and let Oh Dear! doublecheck the uptime from different locations.

We'll do a deeper dive into the Chrome extension at a later point, to show all the details.

Certificate health checks #

Our certificate checks allow you to check the important details of your websites' certificates. We'll check the expiration date, the intermediate & root certificates and some of the encryption algoritms used.

Public Checks - Certificates

We actually check a few extra things that don't quite fit the screenshot, go ahead and scan your own domain to see the results.

What we can't show, and what our subscribers do enjoy, is:

  • Notifications when certificates change (renewals or unexpected changes)
  • Notifications when SANs get added or removed from a certificate
  • Notifications when a root certificate gets revoked and could render your certificates useless
  • Notifications when we detect new certificates for your domains in certificate transparency logs

As you can see, there are still plenty of reasons to give us a try. :-)

Try out the certificate checker at

A crucial piece of our offering is still missing from these public checks: our broken links & mixed content reporting.

These work fundamentally different than the certificate & uptime check. Our crawler can take anywhere between a few minutes up to an hour to complete a run and report the issues with a website.

As a user, you don't want to keep your browser open and wait for that.

We'll create a solution where you can leave your e-mail address and we'll email the report to you as soon as our crawls are done. This takes a bit more work to complete (and we want to get it right - just like the rest of our app).

As soon as that's finished, we'll make sure to blog about it!

Sharing the results #

Every check will generate a unique URL that can be shared among colleagues, friends or on social media.

If there's downtime or an issue with a certificate, this will allow you to provide all the necessary info to those responsible to take action.

Want to get started? We offer a no-strings-attached 10 day trial. No credit card required.

Start free trial »

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