Dirty Talk - How clean is your tech?

Could your tech be harbouring more bacteria than your toilet seat?

We eat at our desks, wear our smartwatches to the gym, snack when we game and use our phones when we’re on the loo. But, be honest, when’s the last time you gave your smartphone, keyboard or video game controller a good clean?

To see just how filthy our gadgets can get, comparemymobile took swabs from various pieces of tech that we use every day to see just what nasties could be lurking on them – as well as giving a few tips on how to them clean them.

We tested smartphones, keyboards, smartwatches and video game controllers for:

  • Total aerobic bacteria count
  • Coliforms: A type of bacteria found in the digestive tract that is also found in waste.
  • Staphylococci: A bacteria that can cause skin infections, boils, styes, abscesses, as well as food poisoning, and in very extreme cases, toxic shock syndrome.
  • Enterobacteriaceae: A bacteria family that includes E.Coli and Salmonella that can cause food poisoning, as well as others that can lead to anything from urinary tract infections to pneumonia.

Smartphone - What we found

We found that a typical smartphone has approximately 100 Colony-Forming Units (CFU) per cm2, but with a toilet seat having an average of 6.51 CFU per cm2, that means that your phone screen could potentially be over 15 times (1,438%) more contaminated that your toilet seat.

Our study also found moderate levels of Staphylococci present (approx. 12 CFUcm2), as well as low levels of Coliforms (0.4 CFUcm2), a bacterium that’s typically found in the digestive system or waste.

The good news is, that when it comes to smartphones, there were little to no Enterobacteriaceae present.

Keyboard - What we found

With people regularly eating or snacking at their desk, you’d think that they’d do their best to keep their keyboard clean, however, we found roughly 40 colony-forming units per cm2 which is 6 times (515%) more than a toilet seat.

Interestingly, keyboards were the only item included in our study that showed a clear presence of all bacteria types, but rather worryingly, it also had the highest concentration of Coliforms.

While maybe not as obvious as the growth on other slides, the darker spots indicate Coliform growth in the region of 2.5 CFU per cm2. Coliforms live in the digestive tracts of animals and humans and are found in their waste, so next time you go to open your mid-morning snack at your desk, you might want to think about washing your hands first.

Controller - What we found

The gamers out there will be relieved to hear that there were only very low levels of Coliforms and Enterobacteriaceae found on our controllers (approx. 0.4 colonies per cm2), but there was still a fair amount of other forms of bacteria present.

We found a concentration of 12 colonies of aerobic bacteria per cm2 – almost twice that of a typical toilet seat – as well as 40 CFU per cm2 of Staphylococci, a bacteria that can cause skin infections, boils and food poisoning.

Smartwatch - What we found

While the results for the smartwatch may not look as disconcerting as others, the fine covering of the slide could indicate a higher concentration of individual colonies resulting in more Colony-Forming Units (CFU) per cm2.

Like the controller, the smartwatch showed low levels of Coliforms and Enterobacteriaceae, but large levels of aerobic bacteria and Staphylococci. In fact, we found between 100 and 2502 colonies of each on the watches surface and strap officially making the smartwatch the dirtiest piece of tech included in our study.



Bacteria present

Bacteria Coloniesper cm (CFU)

% more/less than a toilet seat


Coliforms, Staphylococci




Coliforms, Staphylococci,Enterobacteriaceae








Staphylococci, Enterobacteriaceae



*Total aerobic bacteria colonies

Dan Clifford from comparemymobile commented: “As they say, life’s messy, and with technology being such a big part of both our work and personal lives, that out of the box freshness wears off pretty quickly.

“While it’s pretty shocking to see all the nasty surprises your gadgets could be harbouring up close, it’s important to remember that we come into contact with these things on a daily basis without incident.

“That being said, it’s still a good idea to give things a good clean every so often, especially your phone as it’s the only most likely to come into contact with your face. While many retailers sell phone cleaning wipes, some manufacturers, such as Apple and Samsung, suggest that the harsh chemicals may damage the protective coating on your phone's screen.

“Instead, try turning off your device and cleaning it with a slightly damp lint-free cloth and warm soapy water - but be careful to not get water in the charging port.”

Whether you want to sell your dirty old phone or looking for a new squeaky clean one, compare the best deals with comparemymobile.

Notes to editors:

  1. Bacteria per cm2 for typical toilet seat: bbc.co.uk, “The dirtiest place in your kitchen might surprise you”, Michael Mosley, 21 February 2018.

2Bacteria colonies close to each other may merge giving the appearance of a larger (or fewer) number of individual colonies than are truly present.


  • All items sampled were ‘real world examples’ meaning individuals volunteered personal items for testing to provide a more accurate representation.
  • Samples were taken from three cohorts of each item, colony counts are the average across all samples. Samples were taken using a combination of direct surface and swab testing.
  • Bacteria associated with faecal matter as well as those associated with the opportunistic bacteria Staphylococcus Aureus was specifically tested for.
  • Dip Slides were incubated at 30℃ for 36hrs.
  • Total aerobic bacteria per cm2 was quantified using the comparison chart provided by ‘Dip Slides’.