Gaurav Mantri's Personal Blog.

Simple Calculator for Comparing Windows Azure Blob Storage and Amazon S3 Pricing


I originally wrote this post in September 2012. Recently at their re:Invent event, Amazon announced reduction in their storage prices by 24-28% ( Yesterday Microsoft announced similar price reduction ( I have updated this blog post taking these price reductions into consideration and including them in my calculator below. Please note that both Amazon and Windows Azure have reduced only the storage charges. They have not changed the transaction charges or the bandwidth (Egress) charges. The new prices for Amazon became effective as of 01-December-2012 while that for Windows Azure will become effective on 12-December-2012.

Few months back, I wrote a few blog posts comparing Windows Azure Blob Storage and Amazon S3 services. You can read those blog posts here:

Since pricing for both of these services are changing quite frequently and depended upon a number of factors, it was not possible for me to pinpoint exactly which service is cheaper. I created a simple calculator where you can input appropriate values and compare the cost of both of these services to you.

As mentioned in my other blog posts, the pricing depends on 3 factors in both services:

  1. Transaction costs i.e. cost incurred based on number of transactions performed against each service. These include various REST based operations performed against the two services.
  2. Storage costs i.e. cost incurred based on the amount of data stored in each service. These are usually calculated based on Giga bytes of data stored per month.
  3. Bandwidth costs i.e. cost incurred based on the data sent out of the data center in each service. Please note that at the time of writing of this blog, all incoming traffic is free in both service as well as the data transferred between an application and storage service in same data center is also free.

In this simple calculator, I took only first two factors into consideration. Again when it comes to storage costs, both services offered a tiered pricing scheme, which I have not considered.


A few comments:

  • At the time of writing this blog post, the pricing is taken from respective services pages ( and I will try an keep this post updated with the default pricing however I would strongly recommend that you check the pricing page for respective services to get most current pricing.
  • While pricing is an important criteria, it should not be the sole criteria for deciding which service to choose. One must also consider the features offered by each service. You can check for a feature by feature comparison as of 11th of May 2012. Since then both services have offered some new features (e.g. Asynchronous copy blob support in Windows Azure and CORS support in Amazon S3 etc.) which should also be taken into consideration.
  • For storage costs, I have taken very simple scenario though both services offer tiered pricing as well. One should take that into consideration as well.
  • Lastly, I must emphasize that it is a very simple calculator with no in-built error checking or data validation. If you find any issues with this calculator (especially around incorrect calculations), please let me know ASAP and I will fix them.

Hope this helps.

[This is the latest product I'm working on]