How to use JSON, CSV and YAML converter
- Pick the format you have and the format you want.
- Paste your data. The converted result appears as you type.
- For CSV input, choose whether numbers and true/false become typed values.
- Copy the result or download it as a file.
JSON, CSV and YAML
JSON is what APIs and JavaScript speak. CSV is what spreadsheets open. YAML is what configuration files for Kubernetes, GitHub Actions and Docker Compose are written in. This converter moves data between all three as you type, so you can open an API response in a spreadsheet, turn a spreadsheet export into JSON test data, or rewrite a JSON config as YAML.
From nested JSON to flat CSV
A spreadsheet is a flat grid, but JSON objects nest. The converter flattens each object into columns named with dots, so a field at address.city becomes an address.city column, and joins lists of plain values with semicolons. Every key that appears in any object becomes a column, so records with missing fields leave those cells empty rather than shifting columns. Values containing commas, quotes or line breaks are quoted correctly.
Reading CSV
CSV from Excel, Google Sheets and databases varies. The parser follows RFC 4180, handling quoted fields, doubled quotes and line breaks inside quotes, removes the byte-order mark Excel adds, and detects whether the file uses commas, semicolons (common with European Excel settings), tabs or pipes. The first row becomes the field names.
With typing on, numbers become numbers, true and false become booleans, and empty cells become null. Values with leading zeros, such as 007 or postcodes, stay as text so nothing is lost. Turn typing off to keep every value as text.
Errors and privacy
Invalid JSON is reported with the line and column of the first problem, and invalid YAML with the parser's explanation. Everything runs in your browser; your data is never uploaded or saved.
Common uses
Opening an API response in a spreadsheet to share with a colleague, turning a spreadsheet of products into JSON fixtures for tests, converting a docker-compose or GitHub Actions file between YAML and JSON to inspect it, or moving data between two tools that expect different formats. Download the result with the right extension, ready to open.
Questions
- How are nested JSON objects turned into CSV?
- Nested fields become dotted columns, so {"address": {"city": "London"}} becomes an address.city column. Lists of plain values are joined with semicolons.
- Does it handle CSV from Excel?
- Yes. Quoted fields, commas and line breaks inside quotes, a byte-order mark, and semicolon or tab delimiters are all detected automatically.
- Is my data uploaded?
- No. Conversion runs in your browser and nothing is saved.