The value inspector allows you to inspect and navigate the structure of data. While you can use it for pretty much anything (e.g. primitive data types, var, ref types) it’s most useful when you’re dealing with (deeply) nested collection-like data types (e.g. a vector of maps).


Typing C-c M-i (cider-inspect) after some form in a source buffer or the REPL will show you the structure of the form’s result in a new buffer. You can also use C-u C-c M-i to inspect the result of the current top-level form and C-u C-u C-c M-i to read an expression from the minibuffer and inspect its result.

Alternatively, after a regular eval command, you can inspect the last evaluated value using cider-inspect-last-result. When an inspector buffer is visible in the background, it is automatically updated with the last result. This behavior can be controlled with the variable cider-auto-inspect-after-eval.

The inspector can also be invoked in the middle of a debugging session, see here for more details.

You’ll have access to additional keybindings in the inspector buffer (which is internally using cider-inspector-mode):

Keyboard shortcut Description

Tab and Shift-Tab / kdb:[n] and p

Navigate inspectable sub-objects

f and b

Navigate across characters on a line


Inspect sub-objects


Pop to the parent object


Refresh the inspector (e.g. if viewing an atom/ref/agent)


Jump to next page in paginated view


Jump to previous page in paginated view


Set a new page size in paginated view


Set a new maximum size above which nested collections are truncated


Set a new maximum length above which nested atoms (non-collections) are truncated


Defines a var in the REPL namespace with current inspector value. If you tend to always choose the same name(s), you may want to set the cider-inspector-preferred-var-names customization option.


By default, navigation skips over values like nils, numbers and keywords, which are not interesting to inspect. You can control this behavior using the variable cider-inspector-skip-uninteresting.

The inspector buffer is automatically selected by default. You can disable the auto selection with the variable cider-inspector-auto-select-buffer.

You can set the amount of data shown by default with the variables cider-inspector-page-size, cider-inspector-max-coll-size, and cider-inspector-max-atom-length. The values can be adjusted for the current inspector buffer using the s, c, and a keybindings.

If you enable cider-inspector-fill-frame, the inspector window fills its frame.

Starting from CIDER 1.8.0, when you define a var using d, a var name can be suggested (default none). You can customize this value via the cider-inspector-preferred-var-names configuration option. Even after setting it, you are free to choose new names on the fly, as you type. Most recent names will take priority in subsequent usages.