Charles McQuain

Founder & Editor at AvailSim

About Me

I'm a software engineer who travels internationally multiple times a year. I got tired of wasting hours comparing eSIM plans across a dozen provider websites before every trip — so I built AvailSim.

Every comparison, recommendation, and editorial on this site is written and maintained by me. I use travel eSIMs on my own trips, and I'm transparent about what I've used firsthand versus what's based on published provider data.

My background in software engineering means AvailSim isn't just a blog with affiliate links — it's a data-driven comparison platform built to surface genuinely useful information for travelers.

Areas of Expertise

check_circleeSIM plan comparison and analysis
check_circleInternational mobile connectivity
check_circleTravel technology and tools
check_circleSoftware engineering (Next.js, TypeScript, data systems)

Travel Experience

I've traveled to 12 countries across Asia, Europe, and the Americas — giving me real experience with mobile connectivity challenges in different regions. This isn't theoretical; I've dealt with dead zones, confusing activation processes, and throttled plans on actual trips.

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East Asia

Japan, Hong Kong, China

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Southeast Asia

Thailand

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Europe

Italy, France, England, Northern Ireland, Ireland, Spain

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Central America

Nicaragua

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North America

Mexico

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Recent Trips

Where I've used travel eSIMs myself since launching AvailSim. These were ordinary trips, not structured tests — I haven't yet run head-to-head speed tests, and I don't claim results I don't have:

arrow_forwardMay 2026 — France (Paris): a week on a Saily eSIM, for my dad's 70th birthday
arrow_forwardAugust–September 2026 — Ireland (Dublin) and the UK (London): Ubigi in London with no issues; bought separate Ireland and UK plans where one EU+UK plan would have done

Read more about our testing process on the methodology page.