Bruno is part of the group of tools for sending API requests, alongside Postman and Insomnia. Its approach is different: collections are saved in a plain text markup language as files in a folder, not in a vendor’s cloud. Teams commit them to git, review changes in pull requests, and keep API tests next to the code they test.
You can build requests with variables, scripts, and assertions, run collections for testing, and use it from a command line interface in CI pipelines. It supports REST, GraphQL, and other protocols. Because it works offline and does not require an account, it appeals to developers who dislike mandatory sign-ins and cloud syncing after changes in other tools.
Bruno is free and open source, with paid editions that add features for teams. It is younger than Postman and has fewer integrations and collaboration features. Alternatives include Postman, Insomnia, Hoppscotch, Thunder Client, and curl or HTTPie for the command line. Bruno suits developers who want API tooling that fits into git.