# Can I use an LGPL-2.1 library in proprietary software?

**Short answer:** Shipping a proprietary app that links the library: Yes. Shipping a modified copy of the library: Yes.

LGPL-2.1 lets proprietary programs use the library, provided users can replace or relink the LGPL part and changes to the library itself stay LGPL.

## Shipping a proprietary app that links the library — Yes

License: [GNU Lesser General Public License v2.1 only](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html) (`LGPL-2.1-only`, curated)

- Every use you described is granted by LGPL 2.1, and nothing you described is prohibited.

Duties: attribution, license_notice, state_changes, share_alike, source_disclosure
## Shipping a modified copy of the library — Yes

License: [GNU Lesser General Public License v2.1 only](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html) (`LGPL-2.1-only`, curated)

- Every use you described is granted by LGPL 2.1, and nothing you described is prohibited.

Duties: attribution, license_notice, state_changes, share_alike, source_disclosure

## Context
- Dynamic linking is the usual way to meet the relinking condition; static linking needs object files or an equivalent so users can relink.

## Sources
- [GNU LGPL v2.1](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html)

## Check it yourself (free, no key)
```json
{
  "tool": "check_license",
  "arguments": {
    "license": "LGPL-2.1-only",
    "intended_use": {
      "commercial_use": true,
      "redistribution": true
    }
  }
}
```
REST: POST https://www.rightshold.com/v1/licenses/check

_Computed from Rightshold's license profiles; not legal advice. Updated 2026-10-23. JSON: https://www.rightshold.com/answers/can-i-use-an-lgpl-2-1-library-in-proprietary-software.json_