JSON to CSV Converter: Convert JSON to CSV Online | Free Tool

A Your privacy is a top priority. This free online JSON to CSV converter processes your data instantly in your browser (or without storing it on our servers). We do not store, log, or share any JSON data you paste into the tool. Once the conversion is complete, your input data is purged, ensuring your sensitive information remains confidential and secure throughout the process. You can confidently convert JSON to CSV without privacy concerns.

A Choosing a custom delimiter, like a pipe (|) or tab, is essential when your JSON data itself contains commas or semicolons within its values. Using an alternative delimiter ensures your CSV file maintains correct column separation, preventing data corruption when imported into spreadsheet software. This feature provides flexibility for diverse datasets and ensures smooth data handling.

A Large files can cause browser slowdowns. This tool handles datasets up to 50MB reliably. Beyond that, you'll likely hit memory limits or long processing times. For massive JSON files, split them into chunks first. A practical tip: test with a 1MB sample before converting the whole thing.

A The tool fills empty cells with blank values instead of failing. If your first object has "name" and "age" but the second only has "name", the second row will show an empty cell under "age". This keeps your CSV structure intact. For consistent results, ensure all objects share the same keys.

A Yes, column headers follow your JSON keys exactly as they appear in the first object. If your first entry has "name" before "email", that order sticks. But there's a catch: different browsers may reorder keys when displaying the preview. Download the file and open it in a text editor first to verify. For predictable results, use a JSON array with consistent key ordering across all objects.

A Not really. Browsers cap memory at around 2GB, so arrays over 100,000 rows will likely freeze your tab. For big datasets, split the JSON into 50,000-row chunks or use a command-line tool like jq. Test with 100 rows first—that takes under a second. Your browser's performance also depends on how much RAM your machine has.

A Yes, it preserves UTF-8 characters exactly. Accented letters, Chinese characters, and even emoji like 🚀 stay as-is in the CSV output. One caveat: some spreadsheet apps might mangle these on import. If your CSV shows garbled text, open it in a plain text editor first. For Excel users on Windows, save the file with UTF-8 BOM encoding—our download menu has that option.

A Yes, but you'll end up with lots of empty cells. The tool scans the first 50 objects to build its column list. If object 51 introduces a brand new key, that field gets dropped silently. For a complete CSV, either standardize your JSON keys first or run a quick script to find all unique keys across your entire dataset.

A Yes, but the tool flattens nested structures using dot notation. For instance, {"user":{"name":"Sam"}} becomes a column named user.name with the value Sam. Arrays inside objects get serialized as JSON strings in a single cell. That's usually fine for spreadsheets, but it won't give you relational tables. If you need true nesting, flatten your JSON manually first. This approach keeps the output predictable and avoids surprise empty columns.

A Yes, but you'll get a one-row CSV. The tool treats a single object like a one-element array, so all its key-value pairs become columns. For example, {"id":1,"name":"Sam"} converts to a CSV with headers id and name, and just one data row. That's rarely what people want—most use cases need multiple rows. If you're building an API response, wrap your object in square brackets before pasting it in. You'll save yourself a confusing pivot later.