# H2 Database Engine Welcome to H2, the Java SQL database. The main feature of H2 are: Very fast, open source, JDBC and ODBC API Embedded, server and cluster modes; in-memory databases Browser based Console application Small footprint: around 1 MB jar file size
### Download Version ${version} (${versionDate}):
| Windows Installer (3.3 MB)
| All Platforms (zip, 4.9 MB)
All Downloads
### Support English Google Group Japanese Google Group Or send an e-mail to:
### Features
| H2 | Derby | HSQLDB | MySQL | PostgreSQL
--- | --- | --- | --- | --- | ---
Pure Java | Yes | Yes | Yes | No | No
In-Memory Mode | Yes | No | Yes | No | No
Transaction Isolation | Yes | Yes | No | Yes | Yes
Cost Based Optimizer | Yes | Yes | No | Yes | Yes
Encrypted Database | Yes | Yes | No | No | No
ODBC Driver | Yes | No | No | Yes | Yes
Fulltext Search | Yes | No | No | Yes | Yes
Multi Version Concurrency | Yes | No | No | No | Yes
Footprint (jar/dll size) | ~1 MB | ~2 MB | ~600 KB | ~4 MB | ~6 MB
See also the detailed comparison.
### News Newsfeeds: Full text (Atom) or Header only (RSS). Email Newsletter: Subscribe to H2 Database News (Google account required) to get informed about new releases. Your email address is only used in this context.
### Contribute You can contribute to the development of H2 by sending feedback and bug reports, or translate the H2 Console application (for details, start the H2 Console and select Options / Translate). To donate money, click on the PayPal button below. You will be listed as a supporter: