Select data format to convert
Process structured data, string encoding, and numbers/dates separately by use case.
Before conversion
CSV and XML advanced settings
Conversion result
Encode and decode strings
Conversion result
Base64 is not encryption. It cannot be used to protect credentials or confidential information.
Base conversion
- Binary
- 11111111
- Octal
- 377
- Decimal
- 255
- Hexadecimal
- FF
Unix time conversion
Input is converted only within your browser.
What you can do with the JSON, CSV, XML, YAML data conversion tool
Reads structured data in JSON, CSV, TSV, XML, and YAML, and converts to other formats. For strings, it offers Base64, URL encoding, and HTML entity conversion/restoration; for numbers, binary, octal, decimal, and hexadecimal; for dates, Unix seconds and Unix milliseconds.
Input is parsed entirely in your browser and is not sent to external APIs or WiseChecker processing servers. Even when handling customer data or development configs, be mindful of where you store copies or saved results.
Structured data conversion
Converts while preserving the correspondence among JSON arrays, CSV/TSV tables, XML elements, and basic YAML.
Show error position
Checks JSON syntax errors, CSV quotes, XML parse errors, and YAML indentation.
Unicode-safe Base64
UTF-8 preserves accented characters, emoji, and non-Latin scripts.
Base conversion for large integers
Uses BigInt to handle integers even at digit counts where normal JavaScript numbers would round.
Steps to convert JSON, CSV, XML, YAML
- Choose input formatChoose whether the pasted content is JSON, CSV, TSV, XML, or YAML.
- Choose output formatChoose the format by use case: JSON for system integration, CSV/TSV for spreadsheets, YAML for configuration files.
- Paste input dataCSV delimiters are auto-detected. Line breaks or delimiters within fields are enclosed in quotes.
- Convert and inspect structureCheck the number of array items, object properties, and output character count.
- Copy or saveCharacter encoding is UTF-8. For Excel CSV, also check the encoding setting after saving.
Correspondence when converting between structured data formats
| Input | Handling during conversion | Information that may be lost |
|---|---|---|
| JSON | Preserve arrays, objects, numbers, booleans, and null | In CSV, store nested data as a JSON string in one cell |
| CSV/TSV | Convert the first row to column names and create an array of objects | Reads everything as strings, so type information is not inferred |
| XML | Attributes as @, text content as #text, and same-name elements as arrays | Fine distinctions among namespaces, comments, and CDATA |
| YAML | Process basic arrays, mappings, numbers, booleans, and null | Advanced specs such as anchors, tags, and multiline notation |
CSV conversion works mainly for arrays of objects or simple tables. Deeply nested structures become JSON strings within cells. After conversion, compare the original data for record count, column names, nulls, and leading zeros.
Differences among Base64, URL encoding, and HTML entities
| Method | Use | Note |
|---|---|---|
| Base64 | Represent binary or UTF-8 strings as ASCII characters | Not encryption; anyone can decode it |
| URL encode | Safely represent reserved characters in URL parameters or values | For the entire URL vs. a value, you need to use encodeURI vs. encodeURIComponent appropriately |
| HTML entities | Display <, >, &, and quotes as characters in HTML body text | Security measures for JavaScript or attribute values are needed per output context |
How to distinguish Unix seconds from Unix milliseconds
Unix time is the elapsed time since January 1, 1970, 00:00:00 UTC. Around 10 digits is typically seconds, around 13 digits is milliseconds. This tool displays both and auto-detects based on the input length.
The date-time input is read as your device’s local time, and the result shows both local and UTC representations. Check whether your server logs or API specs use UTC or local time before using.
Data that cannot be converted or needs review
Does not support YAML anchors/aliases, custom tags, multi-document files, complex multi-line strings, or XML DTDs, external entities, or full namespace preservation. External entities are not loaded. For CSV character-set auto-detection or Shift_JIS file reading, use the Excel/CSV Data Fixer instead of this paste field.
Large data uses browser memory. For inputs exceeding tens of MB, use your organization’s official conversion procedures or command-line tools, and verify results by record count or hash values.
Processing without sending input data
Parsing, format conversion, Base64, URL/HTML conversion, base calculation, Unix time calculation, copying, and file creation all run in your current browser. Input values are not sent to servers, external library CDNs, or AI generators. Reloading the page clears input and results.
Data conversion FAQ
Are leading zeros in CSV preserved?
The conversion result is kept as a string. However, Excel may auto-convert numbers when opening CSV, so use the Excel/CSV Data Fixer to specify column types if needed.
Does it support all YAML specifications?
Supports basic mappings, arrays, numbers, booleans, null, and quoted strings. Anchors, tags, and multi-line notation are not supported.
Do you load external XML entities?
Nothing is loaded. It parses the string in the browser and does not access external DTDs or files.
Can Base64 be used for password protection?
No. Base64 is an encoding format, not encryption.
What is the difference between converting the entire URL and converting parameter values?
Converting as a value also encodes / and ?. For the entire URL, delimiters are kept.
Can I convert large hexadecimal numbers?
Integers are handled with BigInt. Decimals and exponential notation are not supported.
Is my input saved?
Nothing is saved or sent. Copy or download any needed results before closing the page.
Related free tools
Practical examples
Convert a small JSON list to CSV for Excel
Choose JSON as input and CSV as output. Try the fictional two-row example below, convert it, and verify the column names and row count before saving. In Excel, import the file and review column types rather than relying on automatic conversion.
Product codes and values with leading zeros may need to stay text. A JSON number uses a decimal point; its visual format in Excel depends on your import and regional settings.
[{"product":"Sample notebook","price":2.5},{"product":"Sample folder","price":1.2}]Check delimiters before changing the format
If a CSV lands in one column, inspect whether the source uses commas, semicolons or tabs. Set the delimiter in the advanced settings and confirm the preview. Keep an untouched copy of the original.
Conversion is not data validation. Check quoted text, blank values and dates; do not assume nested JSON or XML structure maps perfectly to a flat spreadsheet. Start with a small sample.