Format JavaScript and JSX with parser-aware quotes, semicolons and trailing commas, explicit syntax errors and local worker processing before review.
Choose your path
Produce a reviewable JavaScript or JSX formatting diff that respects comments, regex literals, templates and automatic semicolon insertion.
Format JS/JSX without damaging URLs, comments, regexes or templates.
Paste the authored example, choose quote/indent preferences, format and compare source/output.
Receives parser-generated code and copy-only output without appended reports.
Understand semicolon and trailing-comma semantics.
Compare both semicolon styles around for loops and return-newline cases, challenge syntax errors, then recover.
No invalid partial output; formatting is not confused with linting, type checking or execution.
Review and hand off settings without stale output.
Use labeled keyboard controls, change options, rerun and explicitly save to the Project.
Only current output is copyable/savable; JavaScript warning does not collide with SQL.
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.
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Prettier 3.9.6 uses Babel and ESTree plugins. Comments, regex literals and template syntax are parsed before printing. Embedded-language formatting is disabled; source code is never evaluated.
An explicit run loads the language engine in a disposable worker. Cancellation and a wall-clock timeout prevent abandoned work from updating results. Input code is never executed.
Input or option changes invalidate old output. Copy/download contain code only, not an appended report. Formatting is not automatic repair or runtime validation.
Updated: August 2026
Format URL strings, regex literals and nested templates without regex-based substitutions that corrupt their contents.
Correct an incomplete function using the displayed parser error, then format again to replace the empty result.
Save source, formatted JavaScript and a distinct settings/warning note to the REST API Project after checking ASI-sensitive code.
Use the Babel parser through Prettier for JavaScript and JSX. Choose indentation, width target, quote preference, semicolons and trailing commas; compare the result before replacing source.