MySQL and SQL Server are two of the most widely deployed relational databases, but they come from very different worlds. MySQL is open source and free to run, long favored for web applications and the LAMP stack. SQL Server is a Microsoft product with paid editions and first class integration across the Microsoft ecosystem.
MySQL is owned by Oracle and offered both as a free community edition and paid commercial editions, and it is the default database in countless PHP, WordPress and web projects. SQL Server ships in several paid editions plus a free Express tier, and shines inside .NET, Azure and business intelligence workflows with polished tooling like SSMS. This comparison breaks down where each one leads.
Side by side
| Aspect | MySQL | SQL Server |
|---|---|---|
| License and cost | Free and open source community edition (paid commercial editions also exist) | Commercial, paid editions, plus a free Express tier with limits |
| Platforms | Linux, Windows, macOS and most Unix systems | Windows and Linux |
| Primary language | Standard SQL with MySQL extensions | T-SQL |
| Tooling | MySQL Workbench, phpMyAdmin, many CLI tools | Polished first party SSMS and Azure Data Studio |
| Ecosystem | LAMP stack, web apps, WordPress and PHP | Microsoft, .NET, Azure and BI stack |
| Enterprise features | Solid core features, more in paid editions | Rich enterprise features (Always On, Query Store, columnstore) |
| Cloud home | Managed on every major cloud (AWS RDS, Azure, GCP) | Azure SQL family, tightly integrated |
| Best known for | Web and open source stacks, cost | Enterprise Microsoft stacks and BI |
Where each one leads
MySQL strengths
- Free and open source community edition with no license cost
- Huge web ecosystem: LAMP stack, WordPress, PHP and countless frameworks
- Runs everywhere, including Linux and macOS for local development
- Lightweight, easy to set up and widely supported by managed cloud services
SQL Server strengths
- Deep integration with Windows, Active Directory, .NET and the Azure SQL family
- Polished first party tooling and BI stack (SSMS, SSIS, SSAS, SSRS, Power BI)
- Strong enterprise features like Always On availability groups and Query Store
- Commercial support and a large enterprise ecosystem
When to choose each
Choose MySQL if
- You are building a web app or using the LAMP or WordPress stack
- You want to avoid license costs or run on Linux and macOS
- Your team already knows MySQL and standard SQL
- You want a lightweight, cloud neutral open source database
Choose SQL Server if
- You are on a Microsoft stack (Windows Server, .NET, Azure)
- You need the integrated BI and reporting tooling
- Your team already knows T-SQL and SSMS
- You want advanced enterprise features and commercial support
Verdict
There is no universal winner. Choose MySQL when you want a free, open source database for web applications, value portability and low cost, or already live in the LAMP world. Choose SQL Server when you are invested in the Microsoft and Azure ecosystem, need its enterprise features and BI tooling, or want single vendor commercial support. Both run demanding production workloads well, so ecosystem and team skills usually decide it.
Frequently asked questions
Is MySQL free while SQL Server is paid?
MySQL has a free, open source community edition, though Oracle also sells paid commercial editions. SQL Server is commercial with paid editions, but a free Express edition exists with database size and resource limits. Check Microsoft licensing for the current limits.
What is the difference between MySQL SQL and T-SQL?
MySQL uses standard SQL with its own extensions and stored procedure syntax, while SQL Server uses T-SQL, a richer procedural dialect. Everyday SELECT, INSERT and JOIN queries look similar, but functions, variables and stored procedures differ enough that scripts are not directly portable.
Can I migrate from MySQL to SQL Server?
Yes, and tools exist to help, but it takes work: data types, SQL dialects and stored procedures differ. Plan for schema, query and application changes rather than a one click move. You can also compare MySQL vs PostgreSQL if you are weighing open source options.