Glossary
What is a changelog?
A changelog is a project’s own dated record of what it shipped. It is the check on what was said elsewhere: a feature can be promised anywhere, and the changelog says when it arrived.
Updated 19 September 2026
Why does a changelog matter as a source?
It is the least persuasive document a company publishes, and that is its value. Marketing pages describe what a product is meant to be; the changelog records what changed and when. When a founder says on a podcast that a feature is live, the release notes are where that can be checked.
What is the difference between a changelog and release notes?
In practice the words are used interchangeably. A changelog is the running, dated list kept with the code or the documentation; release notes are the write-up that accompanies one version. Both are first-party and dated, which is what makes them usable as evidence.
Can you follow a competitor through its changelog?
For the products that publish one, yes, and it is among the most reliable ways to see direction: what is being deprecated, which integrations arrive, where the engineering effort is going. Its limit is coverage. Many companies publish nothing of the kind, and a changelog never says why a change was made.