Side by side
Altova DatabaseSpy vs ErdDocs
Both stand on database documentation tools. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free trial Windows
DatabaseSpy brings query work, schema design, and data editing into a Windows database client, with charting in Enterprise Edition. Consider the edition features and listed one-time prices alongside the 30-day trial.
Visit Altova DatabaseSpy
Free plan Web
Choose ErdDocs if you need browser-based diagrams and schema documentation from exported relational schemas, especially if the free plan's 25-table drawing limit is enough. Look elsewhere if you need a live database connection or diagrams that represent Django on_delete and default behavior.
Visit ErdDocsThe facts
| Altova DatabaseSpy | ErdDocs | |
|---|---|---|
| Free plan | A free trial | Yes |
| Open source | Not published | Not published |
| Runs on | Windows | Web |
| Lowest paid plan | DatabaseSpy 2026 Professional Edition: €159, paid once | Lifetime license: $9, paid once |
| Plans published | 4 | 2 |
| Maker | Not published | Not published |
| Website | altova.com | erddocs.com |
| On database documentation tools | #19 of 27 | #15 of 27 |
Altova DatabaseSpy: what it does well
- Supports 15 database types.
- Runs queries asynchronously in separate windows.
- Generates complete schema DDL scripts.
- Imports XML and CSV and exports four formats.
- Offers a fully functional 30-day trial.
What to know first
- No free plan is listed.
- Runs on Windows.
- Enterprise Edition is €179, paid once.
- Altova AI subscription is optional.
ErdDocs: what it does well
- Reads schemas from PostgreSQL, MySQL, and multiple frameworks and diagram formats.
- Exports diagrams, SQL DDL, and a printable data dictionary.
- Browser parsing and rendering keep schemas from being uploaded.
- Diagrams support dragging, focusing, hiding tables, and link sharing.
- Lifetime license has no renewal and works offline after activation.
What to know first
- The free plan draws only 25 tables in full.
- Free dictionary access previews three tables, and exports carry branding.
- Schemas must be exported and pasted; ErdDocs does not connect to live databases.
- Django on_delete and default behavior are not drawn; only db_default is represented.
Alternatives to Altova DatabaseSpy Alternatives to ErdDocs The whole list