As a .NET developer, I was quite excited to hear about Windows Azure. It sounded like a less painful version of Amazon's EC2, supporting .NET (less painful in terms of server management!). When I saw the pricing, it didn't look too bad either. That was, until I realised that their "compute hour" referred to an hour of your app running, not an hour of actual CPU time. Wow. This changes things. To keep a single web role running, you're looking at $0.12/hour = $2.88/day = $20.16/week = $86.40/month.

Anyone that's bought hosting for a small site/app recently will know that this is not particularly cheap!

So, recently I've been playing around with Google App Engine. It has this massive problem called Python (and an even bigger one called Java ;o)), but it's such a nice framework/engine to work with that I've somehow overlooked this and started coding with it. There's so much to like about it. Everything is so simple to deploy, and it scales "out of the box". Want Cron jobs? No worries, specify them in a file in your app, and when you deploy, App Engine will pick them up and schedule them. Want to queue up work to process later so that your pages return faster? Task queues do just that. What's more, you get a ridiculous free quota every day. It may be Python, but this sounds tempting, no?

So, I thought it'd be interesting to compare the costs of App Engine vs Azure. I understand this isn't really a like-for-like comparison, but both can achieve the same sort of things, and while all programmers will have a preferred language/framework (I'm no exception), many can be swayed by a cool framework or hosting.

First off, let's compare what you get for free. Bear in mind that Azure is free until the end of January, but since this is a CTP and won't end soon, I'm going to exclude it. Google's free quota currently has no time restrictions.

Windows Azure    Google App Engine   
CPU Hours - 6.5hrs/day
Bandwidth (out) - 1GB/day
Bandwidth (in) - 1GB/day
Storage (DB) - 1GB
Storage Transactions - 10,368,000/day

Well, for free, I think we have a clear winner. If you can run your website/app within the limits above, then you can do it for free with Google. It's worth mentioning that Google let you have 10 apps per account (though you may not balance a single site/app across app instances - they are specifically for separate projects).

But what if you're bigger than that? What if you get Slashdotted or Dugg a lot? You might find you quickly break out of the free limits. How do prices compare?

Windows Azure    Google App Engine   
CPU $0.12/hour $0.10/hour
Note that MS bill "per hour app is running" whereas Google bill "per CPU hour consumed"
Bandwidth (out) $0.15/GB $0.12/GB
Bandwidth (in) $0.10/GB $0.10/GB
Storage (Files) $0.15/GB/month Pricing unavailable (Blobstore)
Storage (DB) $9.99/month (SQL Server up to 1GB) $0.15/GB/month ($0.005/GB/day)
Storage Transactions $0.01/10,000 ?
I can't find any prices for Google App Engine storage transactions, so it's possible there is no charge (though a limit of 140,000,000/day applies)

Well, that's interesting. I was going to try and calculate at what point Azure would become cheaper, but looking at those prices, it just isn't going to happen. Now it's worth pointing out that not all of the comparisons are fair. Google bill per actual CPU hour (so if nobody visits your site, it's not costing you), whereas Microsoft are billing for each hour your app is live and able to respond. There's also a significant difference between SQL Server and App Engine Datastore (and depending on what you're doing, one will have advantages over the other).

I really hope Microsoft re-evaluate their pricing for small apps. It's too expensive to play around with small prototypes at those prices, whereas Google's offering will let me get started completely free, until my app is churning a considerable amount of traffic, and even then, it'll work our cheaper for the same processing/transfer.

Sorry Microsoft. I love .NET and Visual Studio, but Google App Engine is just so easy and cheap that it's going to be my "toy of choice" for my hobby coding for the immediate future!

Also check out our Drone Comparison, Chromebook Comparison, how to easily split Amazon referrals between Amazon US and Amazon UK and Daily $10 Toys.