# How to programmatically upgrade or downgrade a DWG file?

 1. [FAQ](/faq)
2. »
3. [.dwg support](/faq/dwg-support)

Read the source file into an OdDbDatabase object, then save with a target version:

```plaintext
OdDbDatabasePtr db = svcs.readFile(L"input.dwg");
db->writeFile(L"output_2010.dwg", OdDb::kDwg, OdDb::vAC24);
```

Downgrading may lose data if newer objects (e.g. dynamic blocks, annotative scales) cannot be represented in older formats.