Verify

Verify is a snapshot testing tool for .NET that simplifies the assertion of complex data models and documents. During the assertion phase, the test result is serialised and stored in a file named after the test; on the next run, the result is serialised again and compared with that file.

The test fails when the two snapshots do not match, either because the change is unexpected or because the reference needs to be updated, and a diff tool can be launched to review and accept the change. Verify works with the common .NET test frameworks and has extensions for many types of content, such as JSON, images, documents and web pages.

Verify is open source under the MIT licence. Releases after 1 September 2026 are covered by the Open Source Maintenance Fee for organisations that generate revenue and for government agencies, while the source code remains free.