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 (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 (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

Check it yourself (free, no key)

{
  "tool": "check_license",
  "arguments": {
    "license": "LGPL-2.1-only",
    "intended_use": {
      "commercial_use": true,
      "redistribution": true
    }
  }
}

Computed from Rightshold's license profiles; not legal advice. Updated 2026-10-23. JSON · Markdown