Boring product comparison article. I don't think the derivative metric “cash value per page” is useful, as its mixing multiple items of data together; and is very ignorant about people's thinking. Many marketing people think “cash per page” is very important feature of google analytics. There are also quite a few pages on the internet saying that “convenience of delivery is very valuable to millennials”. Example of why I don't value the metric: “shipping page/ interaction”, is not a revenue earner; but needs to be present in some fashion. If I can't get goods delivered to me, I won't click “BUY!"; if the postage fees make up a large proportion of the purchases value, I will think carefully about other ways to get the goods.

IMO the data to deliver to the business should be: time spent on service; user population churn; user population growth; what feature received most attention; wishes/complaints feedback; feature load speed; odd user interactions (like clicking on inert elements). Data to deliver to the dev team involves “dead clicks”, excessive scrolling, JS crashes, 404 errors (frequently these are third party); I would like to report colour contrast and font readability and feature load times.

Metrics in the review on each tool

  • what data is recorded
  • whether targeting mouse-based UI, or mobile; this item exists, as the older vendors existed before mobile apps where very much use
  • lossy/lossless recording; this item exists as google analytics freemium service is lossy
  • what graphing capacity, specifically heatmaps
  • can import/export data?
  • fees for use at scale


  • Hotjar
    • I bumped into hotjar in 2002, this is a long-lived brand/company.
    • Adverts are all focussed on heatmaps 1 for the last 20 years.
    • It supports eye tracking 2, which against most of the market is a killer feature; and inline user surveys. Hotjar and most the market record mouse-events which is technically easier. Most of the texts say hotjar reads mouseevents, and also doesn't support mobile (content published in 2019 and 2020); however 3 now says it supports tap and scroll events in addition.
    • Hotjar says it can keep data for a year; and in-aggregate captures all mouseevents 4.
    • UX analysis is more critical for resource-constrained mobile apps, they are tested alot; but hotjar doesn't support mobile 5.
    • Hotjar supports export of recorded session; but I couldn't find any import option 6.
    • They seem to support reasonable scale of capture [XXX], and I can't find any mention of lossiness.
  • Datadog
    • Covers infrastructure 7 + event tracking + user tracking 8 + derivative metrics.
    • The RUM (user tracking) logs 9 what a user is doing in their browser.
    • Has an agent for a browser 10, and/ or agent on server (for each server that you use) 11. It can capture data from mobile apps 12.
    • Has a heat map plugin 13, and various graphs in the dashboards 14.
    • Has lossless data recording, but they bill you per month of data stored 15. Historically Datadog billed per-server it was installed on; however I think they do not do that anymore.
    • Datadog has an export feature 16.
  • Plerdy
    • The main website is a well organised conversion funnel 17 18, casually mentioning session replay, heatmaps, event tracking, NPS + sales performance, and conversion funnels. Note search engines do not think this is major brand mark, as they also “correct” the name to “elderly”.
    • Plerdy has heatmaps 19. Plerdy does not mention mobile in a useful fashion, so I guess is limited to desktop. They do have several vacious articles defining terms; but never stating whether they support “user tracking on mobile” e.g. 20. UPDATE: 21 does mention mobile.
    • They do not mention lossy/ lossless anywhere that I can find; I would tend to assume lossless by default.
    • One of the services that Plerdy offers is forms (like their conpetitors), and they offer export of this user data 22. Unlike Datadog they do not seem to support export of sessions.
    • Companies like Plerdy are too slippery to list pricing for scale operations in a meaningful fashion; so I haven't looked.
  • Smartlook
    • Smartlook is very focussed on mobile 23, they also support heatmaps, event recording, user journeys, sales funnels 24. There is documentation for ionic mobile framework 25. They also public an API for integrating into your apps 26. The culture expressed by this company is very different from Plerdy.
    • Smartlook specifically mentions “rage clicks”, which this an important utility to make the UI communicate with users clearly 27. My reference this analytical point is 28 29
    • Smartlook doesn't mention lossy or lossless recording; therefore I assume lossless. Smartlook support a range of export options 30
    • Smartlook can record a range of events 31, but they down-play graphing of these at the end; aside from heatmaps.
    • Smartlook inbound advertising/ blogs position the company as optimised to record every session for every user 32
  • Clarity
    • Clarity is free, so no pricing link; it is Microsoft OSS 33.
    • Clarity has heatmaps, session playback, and metrics visualisation as a dashboard 34 35. From the way they emphasise those statements make it seem smaller/ less features than other applications. It has integration to Wordpress.
    • Clarity blogs say it supports user input from phone web apps 36
    • There is no visible mention of lossy vs lossless; so I assume it is lossless.
    • The corporate blog 37 states that clarity recently gained the ability to export recordings.
  • Inspectlet
    • Does eye tracking 38, which is why I mention the tool. Inspectlet also does session recording, A/B testing, feedback surveys, form analytics and error logging 39.
    • Eye-tracking should be applicable to any device; as it is external to the hardware. Note that smaller motions on smaller screens will be harder to track.
    • There are graphs as part of the dashboard 40
    • There is no mention of lossy or lossless recording; so I would assume lossless by default. The native storage length depends on contract type; but data can be downloaded 41.
  • Crazy egg
    • This tool has annoying cookie terms; they wont let you opt out, until you have accepted the default option (i.e. sign the contract, then negiotate what you wanted with the vendor).
  • Sumo
    • Please note there are several companies with similar names. AFAIK, Sumo previously used the brand “king”, or “sumo king” or similar. However, there is a separate company called “call sumo”, with a different colour scheme and logo 42, who track user experience. Thirdly there is “Sumo logic”, who seem very similar tech to datadog 43.
    • They broker many apps/ plugins 44. Due to the confusion on product offering, I have moved this to last slot.
    • In the 2015 edition, it supplied very detailed user tracking data.

Lastly, if you have a dataset, but no current graphing/rendering technology; try 45.

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