> For the complete documentation index, see [llms.txt](https://mikefarah.gitbook.io/yq/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mikefarah.gitbook.io/yq/v3.x/commands/compare.md). # Compare ```bash yq compare ``` Compares the matching yaml nodes at path expression in the two yaml documents. See [path expression](/yq/v3.x/usage/path-expressions.md) for more details. Difference calculated line by line, and is printed out line by line where the first character of each line is either: * a space, indicating no change at this line * `-` a minus ,indicating the line is not present in the second document (it's removed) * `+` a plus, indicating that the line is not present in the first document (it's added) If there are differences then `yq` will print out the differences and exit with code 1. If there are no differences, then nothing will be printed and the exit code will be 0. ## Example data Given data1.yaml ```yaml "apples": are nice somethingElse: cool # this is nice favouriteNumbers: [1,2,3] noDifference: it's the same ``` and data2.yaml ```yaml apples: are nice somethingElse: cool # yeah i like it favouriteNumbers: - 1 - 3 - 4 noDifference: it's the same ``` ## Basic Basic will compare the yaml documents 'as-is' ```yaml yq compare data1.yaml data2.yaml ``` yields ``` -"apples": are nice -somethingElse: cool # this is nice -favouriteNumbers: [1, 2, 3] +apples: are nice +somethingElse: cool # yeah i like it +favouriteNumbers: +- 1 +- 3 +- 4 noDifference: it's the same ``` ## Formatted Most of the time, it will make sense to [format](/yq/v3.x/usage/output-format.md#pretty-print) the documents before comparing: ``` yq compare --prettyPrint data1.yaml data2.yml ``` yields ``` apples: are nice -somethingElse: cool # this is nice +somethingElse: cool # yeah i like it favouriteNumbers: - 1 -- 2 - 3 +- 4 noDifference: it's the same ``` ## Using path expressions Use [path expressions](/yq/v3.x/usage/path-expressions.md) to compare subsets of yaml documents ``` yq compare -P data1.yaml data2.yml favouriteNumbers ``` yields ``` - 1 -- 2 - 3 +- 4 ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://mikefarah.gitbook.io/yq/v3.x/commands/compare.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.