Is CC0-1.0 compatible with GPL-3.0-only?
Yes.
Combined work becomes strong copyleft. Result license is the more restrictive of the inputs. You must satisfy every input license's notice and source-offer terms. Verify pairwise compatibility first.
Resulting work's license: GPL-3.0-only
General guidance, not legal advice.
Obligations when redistributing as open source
- CC0-1.0: No patent grant.
- GPL-3.0-only: retain the copyright notice and license text.
- GPL-3.0-only: state significant changes made to the code.
- GPL-3.0-only: provide complete corresponding source of the combined work.
- GPL-3.0-only: the combined distributed work must be licensed under GPL-3.0-only.
Other distribution models
The verdict is the same under every distribution model; the obligations differ. Check this pair in the tool to switch models.