Turn compressed JavaScript into consistently indented code for reading and debugging—without executing it or uploading it.
Paste code or import one file. Maximum size: 2 MB.
Shortcut: Ctrl/⌘ + Enter · Code is parsed, never executed.
Readable structure, honest limits
Unminifying makes compressed JavaScript easier to inspect by parsing it and printing a consistent layout. It is valuable for debugging a deployed file, reviewing a small third-party script, or learning how control flow is nested. Formatting exposes structure; it does not reconstruct information the minifier deleted.
Use the full JavaScript file when possible. A cut-off function, string, template literal, or comment cannot be parsed.
The parser reads the code without executing it, then adds consistent whitespace, indentation, and line breaks.
Search the formatted result for a known function, URL, event, or error, and use source maps when originals are available.
These small examples show the exact transformation, including the characters that are easy to overlook.
Indentation and spacing make the function boundary and conditional expression visible, while the short parameter name remains unchanged.
The formatter can separate statements, but it cannot know whether either t was originally named double, value, number, or something else.
Understand the format
Minification is lossy. Many different original programs can produce the same compact output after comments, whitespace, and descriptive local names are removed. An unminifier can choose a readable layout, but there is no unique original layout to recover.
A source map is a separate metadata file created during a build. It maps locations in a deployed bundle back to original filenames, lines, columns, and sometimes embedded source content. If debugging production code is the goal, obtain the exact source map matching that exact minified file.
Deobfuscation is also different. Obfuscators may add confusing control flow, encoded strings, anti-debugging behavior, or runtime-generated code. Pretty-printing can help the first inspection, but it does not automatically explain or safely undo those transformations.
Common questions
Unminifying, beautifying, and pretty-printing usually mean adding consistent indentation, spaces, and line breaks to compressed code so its structure is easier to read.
No. It cannot recreate removed comments, original variable names, TypeScript types, JSX, separate source files, or the author's exact formatting. A source map and the matching deployed file are needed for a closer link to original sources.
No. It parses and prints the code but does not evaluate it. The work happens locally in your browser and the input is not uploaded by this tool.
A minifier may replace descriptive local names with short identifiers such as a, b, and c. Formatting can reveal scope and control flow, but it has no reliable record of what those names used to be.
The input may be truncated, copied from inside an HTML script incorrectly, written in JSX or TypeScript, or depend on syntax the parser cannot read. Start at the reported line and column and check whether the complete .js file was copied.
Formatting does not change ownership or license terms. You may inspect code you are authorized to access, but copying, modifying, or redistributing it still depends on its license and applicable law.