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JSON formatter

Type on the left, formatted output on the right; unquoted keys are repaired automatically, with ascending / descending order, one-click minify, copy and download.

Free and no sign-up. JSON formatter computes and renders entirely in your browser; nothing you enter is uploaded.

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Frequently asked questions about JSON formatter

Can keys be written without double quotes?
Yes. Unquoted keys such as {name:"Flora", tags:["JSON"], age:18} are recognised automatically, double quotes are added before formatting, and the result on the right is valid JSON you can copy or download directly; a notice explains exactly what was fixed.
Which other relaxed syntaxes are supported?
Single-quoted strings, // and block comments, trailing commas at the end of objects or arrays, unquoted values (such as {name: Flora}, treated as a string) and number forms such as +1, .5 and 0x1f are all corrected into valid JSON. Numbers with leading zeros (such as 007) are kept as strings so identifiers do not lose their zeros.
Does the fixing change anything inside strings?
No. Strings are carried over as they are, so commas, colons or brackets inside them are never altered; anything that is already valid JSON (including big integers and escapes such as \u4e2d) is left exactly as written. Only single-quoted strings become double-quoted, then unescaped and re-escaped, so the displayed value matches the original intent.
How do fields and tags map when converting between JSON and XML?
Converting to XML turns field names into tags, fields starting with @ into attributes and arrays into repeated tags with the same name; converting back to JSON turns attributes into fields starting with @, merges repeated tags with the same name into an array and turns text-only elements into strings.
Does formatting change the content of my data?
No. Formatting only adjusts indentation, line breaks, key quotation and, optionally, key order. Field values are never touched: string contents, numeric precision and escape sequences are kept exactly as written, and a parse failure points to the exact line and column.
Do I need to register or pay to use JSON formatter?
Almost every tool is free, needs no registration or sign-in and has no usage limit; the few pay-per-use features (such as AI watermark removal, AI image generation, AI upscaling, AI annotation, and AI flowchart, mind-map and Mermaid generation) state their prices on the page.
Is the data I process with JSON formatter uploaded to a server?
No. Calculation and rendering run locally in the browser and your input is never sent to a server; only the IP address page asks our backend for your outbound address when it opens, and that request carries none of your input. Features that need the backend (such as AI watermark removal, AI image generation, AI upscaling, AI annotation, AI flowchart and mind-map generation and "Financial statements – Small Business Accounting Standards") state their upload scope on their own pages.

About Local Toolbox

Local Toolbox gathers the small tools you reach for every day into one place: formatters, encoding converters, date maths, ID card and address parsing, image and QR code handling, password and amount conversion. Open a page and start working — no sign-up, and almost every tool has no usage limit.

Most features compute inside your browser, so your input never leaves your device; the pages are plain static assets, load fast and keep working offline. The IP page asks our backend for your outbound address when it opens and sends none of your input. AI watermark removal, AI background removal, AI image generation and AI upscaling send content to our backend for inference (watermark removal is ¥1 per run; background removal is ¥1 per run; image generation and upscaling are priced by resolution — 2K ¥2, 4K ¥3); AI annotation sends images to a large model that locates the target and returns coordinates (¥0.5 per image, refunded only when every image in the batch fails); AI flowchart, AI mind-map and AI Mermaid chart generation send your text description to a model that builds the diagram (three separate products, charged ¥0.5, ¥0.5 and ¥0.5 per run respectively); and the accounting helper sends the income, expense, social-insurance and balance figures you fill in to generate a report (¥0.5 for the spoken analysis, ¥1 for the report). These features accept Alipay only, upload nothing before payment succeeds, and refund automatically if processing fails.

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