What's the difference between JSON, JSONC, and JSON5?

Strict JSON (RFC 8259) doesn't allow comments, trailing commas, single-quoted strings, or unquoted keys. JSONC ('JSON with Comments') is a common Microsoft variant used in tsconfig.json and VS Code settings — adds // and /* */ comments and trailing commas. JSON5 is a broader spec that adds single-quoted strings, unquoted keys, hex literals, NaN/Infinity, and more.

What syntax does this parser accept?

// line comments, /* block comments */, trailing commas in objects and arrays, single-quoted strings, unquoted object keys (alphanumeric + _ $), hex escapes (\xNN), and NaN/Infinity. Covers nearly all real-world JSONC and JSON5 files. For full spec compliance, the official json5 npm package is more strict on edge cases.

Why doesn't strict JSON allow comments?

Crockford's original JSON spec deliberately omitted comments to keep the format minimal and discourage parsers from drifting toward JavaScript. The JSONC / JSON5 variants exist precisely because config files benefit from comments — tsconfig.json, package.json (sometimes), .vscode/settings.json all rely on JSONC.

Will the output preserve the comments?

No — strict JSON has no comment syntax, so they're stripped. If you need to preserve documentation, move the comments into a separate _doc field with the comment text as the value, or keep the JSONC original alongside the strict output.

How are trailing commas handled?

Silently accepted and dropped. {"a": 1, } becomes {"a": 1}. [1, 2, 3,] becomes [1, 2, 3]. Both at the end of a value list and after the last element of a single-element collection.

What about single-quoted strings?

Accepted and converted to double quotes in the output. {'a': 'b'} becomes {"a": "b"}. Embedded escape sequences (\n, \t, \u00xx) are processed identically in both quote styles.

Will this parse a tsconfig.json file?

Yes — tsconfig.json uses JSONC, and this parser handles all the JSONC features (comments, trailing commas) it uses in practice. Paste your tsconfig.json or .vscode/settings.json and you'll get strict JSON back.

Is the input sent to a server?

No. The parser runs entirely in your browser. Your input never uploads — safe for config files containing tokens, internal hostnames, or secrets.

JSON5 / JSONC Parser — Free Online

JSON5 parser online — parse JSON5 / JSONC (tsconfig.json, VS Code settings) with comments and trailing commas. Convert to strict JSON, browser-based.

Parse JSON with comments and trailing commas online — convert JSONC (the format used by tsconfig.json and .vscode/settings.json) and JSON5 to strict JSON that any parser will accept. Single-quoted strings, unquoted keys, and block / line comments all handled.

Need to format strict JSON? JSON Formatter. Sort keys? JSON Sort. View as a tree? JSON Viewer.

Indent

JSON5 / JSONC input

Strict JSON output

How to Parse JSON5 / JSONC to Strict JSON

Paste JSON5 or JSONC
tsconfig.json, .vscode/settings.json, a config with comments and trailing commas, a snippet using single quotes — anything that strict JSON.parse rejects.
Click Parse to JSON
PDFFlare strips comments, accepts trailing commas, and converts to strict JSON. The output is what JSON.parse would accept.
Copy and use anywhere
Drop the strict JSON into any system that doesn't accept JSONC — APIs, databases, JSON-only config loaders.

When Do You Need a JSONC / JSON5 Parser?

tsconfig.json review: You want to inspect a tsconfig in a tool that only speaks strict JSON. Paste, parse, get clean output.

Migrating from JSONC to JSON: You're moving config out of JSONC into a system that only accepts strict JSON (databases, some CI tools). Convert all the comment-bearing files in one go.

Debugging config drift: Compare two .vscode/settings.json files structurally. JSON Diff expects strict JSON — parse JSONC first, then diff.

JSON-only API ingestion: The source provided JSON5; the sink only accepts strict JSON. Convert in the middle without writing custom code.

Why Use PDFFlare for JSON5 / JSONC Parsing?

Real-World JSONC Coverage

Comments, trailing commas, single quotes, unquoted keys — handles the cases that show up in tsconfig.json, VS Code settings, and most JSON5 configs.

Pretty-Printed Output

Configurable indentation (2 spaces, 4 spaces, tab) so the output matches your project's style.

100% Browser-Based

Configs stay on your device — safe for tsconfig, settings.json, or any internal config with secrets.

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Frequently Asked Questions About JSON5 / JSONC Parser

JSON Formatter

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JSON to YAML

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JSON Diff

Compare two JSONs structurally

JSON Generator

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