jless

jless is a free command-line viewer for reading, exploring, and searching JSON data. It formats JSON for easier reading, adds syntax highlighting, and lets users expand or collapse objects and arrays with vim-inspired commands. Search supports both full-text and regular-expression queries. jless reads files or standard input, including newline-delimited JSON, and can display YAML when it detects the file extension or when run with the --yaml flag. YAML comments and anchors are not shown. Commands can copy values, keys, and paths to the system clipboard or print them in the terminal; users can also obtain a jq-style path for the focused node, but jq querying is not supported. Data mode provides a streamlined view, while line mode displays formatted JSON. The project is MIT-licensed, written in Rust, and available for macOS and Linux as a standalone binary. Installation options include Homebrew, MacPorts, Linux package managers, Cargo, and downloadable binaries. The project suggests it for exploring external APIs or debugging request payloads. It does not yet support a configuration file.

jless provides terminal-based inspection, navigation, and search for JSON, with YAML display and clipboard commands. It is limited to macOS and Linux and does not provide jq querying or a configuration file.

jless suits developers and others who want to inspect JSON or YAML from a terminal, including when exploring APIs or debugging request payloads. It is available for macOS and Linux.

jless is a terminal viewer for exploring structured data, best suited to developers who inspect JSON or YAML while working with APIs and request payloads. Its keyboard navigation and search make it a focused inspection tool, but it is not a substitute for jq when you need to query or transform data.

Overview

jless turns nested JSON into a navigable, syntax-highlighted view, with controls to expand or collapse objects and arrays. Vim-inspired commands suit keyboard-driven work, while data and line modes offer a streamlined view or pretty-printed JSON. It reads files, standard input, and newline-delimited JSON, so it can fit into a terminal workflow without requiring input to be saved as a file.

YAML display extends that workflow: jless detects it from a file extension or accepts the --yaml flag. It omits YAML comments and anchors, however, so it is for examining data structure rather than preserving all source annotations.

Key features

• Search: Full-text and regular-expression search help locate content in unfamiliar input. This makes jless useful for investigation, but not for extracting or transforming matching data.
• Navigation and paths: Expand and collapse nested structures, then copy or print the focused value, key, or path. A jq-style path can help carry an inspection into a separate jq command; jless itself does not run jq queries.
• Clipboard and terminal output: Commands can copy or print values, keys, and paths, including unescaped string contents. Clipboard access is convenient, though building clipboard support from source on Linux requires X11 libraries.
• Installation: Options include Homebrew, MacPorts, Linux package managers, Cargo, downloadable binaries, or building from Rust source. The project is written in Rust and can be installed as a standalone binary.

Pricing

jless is free: the Free plan costs nothing and includes the MIT-licensed command-line tool for macOS and Linux. There is no free trial because the software is already free, and no paid tier is needed to use its viewer features. The trade-off is scope rather than a free-plan cap: jless does not provide jq querying, and the project does not yet support a configuration file.

Platforms

jless supports macOS and Linux. Its installation choices include platform-specific package managers and downloadable binaries, but there is no Windows version among its supported platforms. The MIT License and standalone-binary option make it a straightforward fit for users comfortable installing terminal software.

Who it's for

Choose jless if you regularly inspect external API responses, debug request payloads, or need to browse nested JSON and YAML from a terminal. It is especially well suited to users who prefer keyboard navigation and want to search or copy a focused value or path. Look elsewhere if you need to run queries, preserve YAML comments and anchors, configure the viewer, or use Windows.

Pros and cons

• Pro: Reads files, standard input, and newline-delimited JSON, which lets it handle both saved data and terminal-fed input.
• Pro: Search, expandable structures, and copyable paths support quick exploration without requiring a separate graphical viewer.
• Con: It is an inspection tool, not a query engine; jq-style paths are useful to pass along, but jless cannot execute jq queries.
• Con: macOS and Linux are the supported platforms, and Linux clipboard support from source requires X11 libraries.
• Con: No configuration file is supported yet, limiting users who want to customize the viewer's setup.

Alternatives

For another terminal-oriented option, consider gojq, a free MIT-licensed CLI and Go library available for Linux, macOS, self-hosted use, and Windows. Choose jq instead when the priority is a free MIT-licensed tool with standalone binaries for Linux, macOS, and Windows. For Android, jidoujisho is a free, open-source option for Android 7.0 and later.

JSONBuddy offers a free personal and educational perpetual license with standard-like functionality and free minor updates, as well as a trial; it is aimed at personal or educational Windows use. Dadroit JSON Viewer has a free non-commercial plan that opens files up to 50 MB and converts JSON to CSV or XML, with a paid Standard plan at $98 per y. Those options fit readers who want a graphical viewer or conversion features rather than jless's terminal navigation.

JSON Crack is a free, open-source online tool for extension and web use, with an approximately 300 KB limit depending on data complexity and hardware. JSON Editor is a free MIT-licensed JavaScript library for self-hosted or web use that requires a modern browser. For more options, browse JSON Tools.

Verdict

jless is a strong choice for macOS and Linux users who want to navigate, search, and copy details from JSON or YAML directly in a terminal. Its focused viewer workflow is the reason to choose it; the absence of jq querying, configuration support, and Windows support are clear reasons to look elsewhere.