Azure Blob Storage is Microsoft’s object storage solution for the cloud. 

It’s a massive, scalable repository where you can store any type of unstructured data—documents, images, videos, backups, log files, and more. It integrates nicely with other Azure services, and it’s secure and reliable. 

Whether you’re migrating from on-premises storage, building new cloud-native apps, or looking to archive files for the long term, Blob Storage is worth looking at. 

“But how much does it cost?”, you ask. “It depends on what you need”, we answer—which is annoyingly unspecific, but it’s the truth. 

Blob Storage offers a pay-as-you-go model that can scale from gigabytes to petabytes without complicated infrastructure planning. 

It’s flexible—you can store virtually unlimited data while paying only for what you use. But this can make pricing confusing if you don’t understand the various tiers, redundancy options, and operational costs involved. 

So, we’ll break down the costs below and explain all the different options you need to know about. 

One major advantage of Azure Blob Storage is its versatility. Here are some common ways you can make use of it: 

• Backup and archiving – Store infrequently accessed data like backups and archives at a fraction of the cost of on-prem solutions 
• Media storage – Host videos, images, and audio files for websites and applications 
• Log and metrics collection – Capture machine-generated data like logs, metrics, and IoT telemetry 
• Data lakes – Store massive amounts of raw data for big data analytics 
• Document repositories – Maintain version-controlled document libraries 
• Cloud-native application storage – Serve as the persistent storage layer for modern applications 

Azure Blob Storage is a cloud service accessible globally over the internet, so you don’t need to be on Azure infrastructure to use it. It’s accessible over HTTP/HTTPS via its REST API or SDKs, meaning you don’t need to be running on Azure to store or retrieve data from it. You just need the appropriate credentials and network access to the storage account endpoint. 

If you get to grips with its complete pricing structure upfront, it’ll help avoid unexpected costs later. 

To get an estimate of costs, you’ll be using Microsoft’s own Azure Blob Storage Pricing Calculator.  

As you’ll see, the pricing you get is dependent on the options you choose —and there are loads of them. These are the four main options you’ll choose from the drop-down menu on the pricing calculator.  

1. Namespace structure – Flat namespace (traditional blob storage) or hierarchical namespace (supports NFS v3.0 and SFTP protocols) 
2. Redundancy options – From locally redundant storage (LRS) to geo-zone-redundant storage with read access (RA-GZRS) 
3. Region – Prices vary by Azure region (we’ll use UK South in our examples). 
4. Currency – What type of money you want to pay with. 

Options are presented with different access tiers – From premium (highest performance, highest cost) to archive (lowest cost, retrieval delays). We’ll explain everything below. 

Flat vs hierarchical namespace: what’s the difference? 

Choosing between these affects both functionality and price. 

Flat namespace is the traditional blob storage structure. It organises data in a simple container/blob model, which works well for most general storage scenarios. This is typically the most cost-effective option for simple storage needs. 

Hierarchical namespace adds a directory layer to organise your data, supporting protocols like NFS v3.0 and SFTP. This makes it compatible with traditional file systems and ideal for data lake storage. While slightly more expensive, it provides significant benefits for analytics workloads and structured data management. 

The hierarchical option effectively transforms Blob Storage into Azure Data Lake Storage Gen2, giving you the best of both worlds: the cost-effectiveness of blob storage with the organisational benefits of a file system. 

• Choose flat namespace for general object storage, backups, static website hosting, and media content 
• Choose hierarchical namespace when migrating from on-premises file systems, working with big data analytics, or requiring NFS/SFTP access 

Most businesses starting with Azure Blob Storage will be well-served by the flat namespace option unless they have specific requirements for file system compatibility or advanced data lake features. 

Redundancy options explained 

Redundancy is the replication of data across multiple locations to make sure your data stays available in the event of hardware failures or disasters. 

Redundancy affects both availability and price: 

• Locally Redundant Storage (LRS): Lowest cost option, data replicated within a single data centre 
• Zone Redundant Storage (ZRS): Data replicated across three availability zones in a region 
• Geo-Redundant Storage (GRS): Data replicated to a secondary region hundreds of miles away 
• Read-Access Geo-Redundant Storage (RA-GRS): Like GRS but with read access to the secondary region 
• Geo-Zone-Redundant Storage (GZRS): Combines ZRS with replication to a secondary region 
• Read-Access Geo-Zone-Redundant Storage (RA-GZRS): Like GZRS but with read access to the secondary region 

Each step up in redundancy increases your costs but provides additional data protection. For critical business data, you’d usually want to go for at least ZRS. 

Access tiers overview 

Access tiers in Azure Blob Storage are sorted by how frequently data is accessed, which directly influences retrieval speed (and cost). These tiers go from Premium for high-performance needs to Archive for long-term, rarely accessed data. 

Here’s a quick rundown of what each tier is best for: 

• Premium: Highest performance using SSD storage, best for applications needing ultra-low latency 
• Hot: For frequently accessed data with lowest access costs but higher storage costs 
• Cool: For infrequently accessed data (stored for at least 30 days) with lower storage costs but higher access fees 
• Cold: For rarely accessed data (stored for at least 90 days) with very low storage costs but significant access charges 
• Archive: For long-term data retention (stored for at least 180 days) with the lowest storage costs but highest retrieval charges and hours of retrieval latency 

Based on the most recent pricing data from Microsoft, here’s what you can expect to pay for blob storage in the UK South region with locally redundant storage (LRS) and flat namespace: 

These are the pay-as-you-go prices, in gigabytes per month.  

Reserved capacity can save you money 

For predictable storage needs, Azure offers reserved capacity options that can significantly reduce your costs. Reserved capacity can be purchased in 100TB or 1PB increments with 1-year or 3-year commitments. These are per-month prices. You can pay up-front or in monthly payments.

For large storage needs, the savings can be substantial compared to pay-as-you-go pricing. 

Does the discount make sense? Well, let’s look at storing 100TB per month on the Hot tier.  

100TB = 102400GB 

50TB = 51200GB 

On the Hot tier, the first 50TB are priced slightly higher than any more you add. So on Pay As You Go, it’d look like this:  

51200 x £0.0142 = £727.04 

51200 x £0.0138 = £706.56 

= £1433.60 

But if you reserved that amount up-front, you’d pay £1204 on the one-year agreement or £969 on the three-year deal.  

That’s a saving of 16% and 32% respectively—certainly worth considering.  

When budgeting for Azure Blob Storage, you might focus only on the base storage costs but overlook the additional charges that can significantly impact the total bill. You’ll definitely want to budget for more than those base costs, especially if you’ll be moving data in and out a lot.  

Here are some of the potential extra costs to be aware of (all prices based on hierarchical namespace, LRS redundancy, UK South region): 

Data operations costs: 

• Write operations: £0.0575 per 10,000 operations for Hot tier (varies by tier) 
• Read operations: £0.0045 per 10,000 operations for Hot tier (dramatically higher for Archive at £5.1451) 
• Archive High Priority Read: £60.6729 per 10,000 operations (when you need urgent access to archived data) 
• Data retrieval charges: Free for Hot and Premium tiers, but £0.0083 per GB for Cool tier and £0.0156 per GB for Archive 

Feature-specific charges: 

• Change feed tracking: £0.010 per 10,000 blob changes 
• Encryption scopes: £0.9335 per month (for container or blob-level encryption) 
• Blob inventory reports: £0.003 per million objects per report 
• Blob Index: £0.0281 per 10K tags (for searchable metadata) 
• SFTP protocol access: £0.23 per hour when enabled 
• Data transfer for geo-replication: £0.0150 per GB for cross-region data movement 

In general, these are useful for more advanced tracking of the coming and goings of your data, as well as boosted security and functionality. They might not be relevant for every use case. 

In any case, when you’re moving data around, there are a few more charges to watch out for. 

Charges for egress—data sent from Azure to an external location—can add up quickly. Outbound data transfer fees depend on the amount of data leaving Azure’s region, and these are different from storage capacity charges. Data moved within the same Azure region (intra-region) is usually free, but data sent out of Azure often incurs extra costs. 

Every API call made to Blob Storage is considered a transaction, and these count towards your monthly bill. For example, reading and writing objects, copying blobs, or listing containers can each increase your transaction costs. Even frequent read or write operations will add up, so it’s important to track the type and number of transactions to manage your expenses. 

Look at your expected usage patterns carefully and use the pricing calculator to include all these factors. 

For large-scale deployments, we suggest enabling alerts with Azure Monitor for unexpected spikes in operation counts, as these can sometimes shed light on inefficient application code or unexpected access patterns. 

As a Microsoft Azure-focused MSP, we sometimes advise clients on how Azure storage options compare with alternatives. Here’s our take on how Blob Storage measures up against other common storage services. 

Azure Blob Storage vs Azure File Storage: what’s the real difference? 

These are two distinctly different storage services, each with its own purpose: 

• Blob Storage is optimized for storing massive amounts of unstructured data like documents, videos, backups, and log files. 
• Azure Files provides fully managed file shares accessible via industry-standard SMB and NFS protocols. 

From a pricing perspective, Blob Storage is definitely more economical for pure data storage: 

Azure Files also has a ‘Transaction Optimised’ tier, which is around 3x more expensive than the Hot tier. It’s for transaction-heavy workloads that don’t need low latency (like migrating data into file shares). 

These are Pay As You Go prices on HDD drives—you can play around with the Azure Files Pricing Calculator for more specific estimates. As with Blob Storage, you can reserve capacity for a discount if you commit long-term, and you can pay extra for high-performance SSDs. 

We typically recommend Azure File Storage only when shared file system access is required, like for application migration scenarios where legacy systems expect a traditional file system structure. For everything else, Blob Storage offers better value.  

(Looking for more guidance on Azure storage options? Check out our Azure Storage Masterclass.) 

Amazon S3 vs Azure Blob Storage: the cloud giants face off 

For companies already using other Azure services, the integration benefits often outweigh the minor price differences between Azure Blob Storage and Amazon S3. However, it’s worth noting the current price comparison: 

Amazon S3 has even more classes like Glacier and Deep Archive for very low-cost storage, starting at about £0.003 per GB/month. Azure, though, offers an archive tier around £0.0016 per GB/month. You’ll also want to compare egress and operations costs, which can vary between platforms. 

We believe that Azure Blob Storage offers great value for money when properly configured. The key is understanding your actual usage patterns and choosing the appropriate tiers. 

In general, we find that a mix of storage tiers delivers the best balance of performance and cost. Frequently-accessed data belongs in the hot tier, while data that ages gracefully can automatically transition to cool and eventually archive storage through well-designed lifecycle policies.

What makes Azure Blob Storage ideal for us is its tight integration with the broader Azure ecosystem. If you’re already using Azure services, the connectivity and unified management experience often outweigh minor price differences with competitors like Amazon S3. 

We’d recommend Azure Blob Storage for businesses of all sizes, but with two important caveats: take the time to properly plan your storage architecture, and use monitoring to catch unexpected usage spikes.  

Need help optimising your Azure costs—for storage and beyond? That’s exactly what we do best at Synextra. Get in touch with our friendly team today.