🔄 CSV to JSON Converter
Paste or upload CSV, get clean JSON instantly. Auto type inference, delimiter detection, multiple output formats. Free, private, no signup.
About This CSV to JSON Converter
This CSV to JSON converter transforms any comma-separated values file into clean, structured JSON instantly in your browser. Paste CSV data or upload a file, and the output appears immediately — no server round-trip, no data leaving your device. Whether you are migrating spreadsheet exports to an API, preparing data for a database import, or converting analytics reports, a fast CSV to JSON converter removes the need to write one-off parsing scripts.
What makes this CSV to JSON converter stand out is automatic type inference. Most tools return
every value as a string, leaving you to cast numbers and booleans manually. This tool detects
column types across all rows and converts "42" to 42,
"true" to true, and empty cells to null automatically.
A type badge below each column name shows the detected type so you can verify it at a glance.
Delimiter Auto-Detection
This CSV to JSON converter automatically detects whether your data uses commas, semicolons, or tabs as the field separator by analysing the first row. European spreadsheets commonly use semicolons; TSV exports from databases use tabs. You can also override detection manually with the delimiter selector if auto-detection chooses incorrectly.
Three Output Formats
Depending on where your JSON is going, a good CSV to JSON converter needs to support different structures. Array of Objects is the most common — each row becomes an object with named keys. Array of Arrays preserves the raw grid structure including the header row. Keyed by First Column indexes each row by its ID or name, which is ideal for lookup tables and dictionaries.
Type Inference — How It Works
The type inference engine checks each value before assigning it to the output. Numbers and
floats are cast using Number(). The strings "true" and
"false" become JSON booleans. Empty strings and the literal "null"
become null. All other values remain strings. You can disable type inference
with the toggle to keep every value as a raw string — useful when working with IDs or codes
that look like numbers but should not be cast.
Who Uses a CSV to JSON Converter?
A CSV to JSON converter is useful across many workflows: importing spreadsheet exports into REST APIs, seeding test databases from CSV fixtures, converting analytics reports to JSON for charting libraries, and preparing configuration data for web apps. This CSV to JSON converter runs entirely client-side — nothing is uploaded, stored, or logged.
Frequently Asked Questions
What is a CSV to JSON converter?
A CSV to JSON converter is a tool that transforms comma-separated values data — the format used by spreadsheets — into JSON used by APIs, databases, and web apps. This tool also auto-detects value types so numbers, booleans, and nulls are correctly represented in the output rather than all being plain strings.
How do I convert CSV to JSON?
Paste your CSV into the input area or upload a .csv file. The tool parses the data instantly using the first row as headers by default, then shows a live JSON preview. Choose your output format, set indentation, and click Download JSON or Copy to clipboard.
Does this CSV to JSON converter support different delimiters?
Yes. This CSV to JSON converter automatically detects whether your file uses commas, semicolons, or tabs as the delimiter by checking the first row. You can also override detection manually using the delimiter selector if the auto-detected value is incorrect for your data.
What output formats does this CSV to JSON converter support?
Three output formats are available: Array of Objects (each row becomes {"name":"Alice","age":28}), Array of Arrays (preserves grid structure with header row), and Keyed by First Column (indexes rows by their first field value). Choose the format that matches your API or database schema.
Is this CSV to JSON converter free to use?
Yes, completely free with no account required. All conversion happens locally in your browser — no CSV data is uploaded to any server, and nothing is stored or logged. Convert as many files as you like at no cost.