CSV to JSON
Convert CSV data and files into clean JSON arrays, with header, delimiter, and formatting options.
CSV data and files are processed locally in your browser and are not uploaded to TechFixGen. The generated JSON stays in your browser unless you copy or download it.
Paste CSV data or choose a file to convert it to JSON here.
Your data stays private
This tool runs directly in your browser. The content you enter is processed locally and is not sent to TechFixGen servers. No account or signup is required.
CSV to JSON conversion guide
What this converter does
CSV-to-JSON conversion turns a comma-separated table into a JSON document — by default an array of objects in which the first CSV row becomes the property names and each following row becomes one object. Developers convert CSV to JSON to load tabular data into APIs, seed databases, build fixtures for tests, or transform exported reports into shapes that JavaScript can read natively. Paste CSV text or choose a local .csv file, and the converted JSON appears instantly under the "JSON output" panel.
Headers and no-header mode
The "First row contains headers" option is on by default: row one supplies the object keys and the rows below become the objects. Turn it off and every row is converted using generated keys named column1, column2, column3, and so on, with no values promoted into keys. The option is a checkbox, so the same file can be converted either way and the summary updates live.
Empty and duplicate headers
Headers are resolved deterministically so columns are never dropped and values are never overwritten. An empty or whitespace-only header becomes columnN (its 1-based position), and a repeated header keeps its original text on first use while later repeats get _2, _3, … suffixes. For example name,name,city converts using the keys name, name_2, city. Legitimate headers are preserved as-is; only genuinely empty or duplicated ones are adjusted, and each adjustment is announced in the warnings box.
String preservation
CSV cells are textual by nature, so every value stays a string. A cell like 00123 remains "00123" and is never silently coerced into the number 123, which protects identifiers, postal codes, and other leading-zero data. Empty cells become empty strings ("").
Delimiters and quoting
The converter shares the CSV Viewer's parsing foundation and understands the same four separators: Comma (,), Tab, Semicolon (;) and Pipe (|). Auto Detect scores each candidate outside quoted content and picks the most frequent separated value deterministically. Quoted fields may contain delimiters and span multiple lines; a literal quote is written as two quotes ("") and a backslash before a quote is also accepted. Both CRLF and LF line endings work. An unclosed quote produces a warning and the value is kept as-is.
Uneven rows
Rows with more or fewer values than the header do not fail the conversion. Missing cells become empty strings, and cells that appear past the last header get a generated columnN key so nothing is dropped. The shared parser flags row-count mismatches as warnings, so you can verify the data still lines up.
Formatting, copy and download
Output defaults to readable pretty-printed JSON and can be switched to Minified. When pretty, an Indent control chooses 2 or 4 spaces. Copy JSON writes the output to your clipboard, and Download JSON saves it as a .json file — named after your source file (for example customers.csv becomes customers.json) or converted.json for pasted text. Both actions use browser APIs only, with no server round-trip.
Privacy
Conversion happens locally in the browser. The source CSV and the generated JSON are not uploaded to TechFixGen, are not sent as part of analytics events, and are not saved in the URL, localStorage, or sessionStorage. The JSON leaves your device only when you click Copy or Download.
Frequently asked questions
How do I convert CSV to JSON?
Paste CSV text into the input area or choose a local .csv file. The converter turns the first row into property names and each following row into an object, producing a JSON array that updates live. Use the Delimiter control for separators other than commas, toggle the header option if your file has no headers, then copy or download the result.
Does CSV to JSON conversion happen locally?
Yes. Conversion runs entirely in your browser. The source CSV and the generated JSON are not uploaded to TechFixGen and are not sent inside analytics events. Copy writes the output to your clipboard and Download saves it via your browser; both happen only when you click them, and reloading the page clears the workspace.
Are CSV numbers converted into JSON numbers?
No. CSV cells are treated as text, so values stay strings. For example 00123 becomes "00123" rather than the number 123, which keeps leading zeros and identifiers intact. Empty cells become "". Use a follow-up step in your own code to parse specific fields into numbers if you need numeric JSON values.
Can the converter handle commas inside quoted values?
Yes. Fields wrapped in double quotes may contain delimiters and newlines, and a literal quote is written as two quotes (""). The shared parser keeps such cells intact, so a value like "Hello, world" converts to a single string.
Does it support semicolon or tab-delimited files?
Yes. Comma, Tab, Semicolon and Pipe are all supported. Auto Detect checks how often each separator appears outside quoted content and favours the header line; if a file is ambiguous, choose the exact separator from the Delimiter control.
What happens if CSV headers are duplicated?
Duplicate and empty headers are handled deterministically so no column disappears and no data is overwritten. The first occurrence keeps its text; repeats get _2, _3, … suffixes (name, name_2, name_3), and empty headers become column1, column2, … The changes are listed as warnings so you can review them.
What happens to rows with more or fewer columns?
They still convert. Missing cells become empty strings and extra cells beyond the last header receive a generated columnN key, so no values are dropped. A warning is shown whenever a row's value count differs from the first row.
Can I upload a CSV file?
Yes. Switch to File mode, choose a local .csv, .tsv or .txt file, and it is read as plain text in your browser. Files up to 10 MB are supported; larger files are rejected with a clear message. The file is processed in your browser and is not uploaded anywhere.
Can I download the converted JSON?
Yes. Download JSON saves the output using a browser Blob API, with no server involved. An uploaded customers.csv produces customers.json; pasted content downloads as converted.json.
Can the converter handle Windows line endings?
Yes. Both CRLF and LF line endings are accepted, and a quoted value may span multiple lines. Trailing newlines and blank lines are handled predictably so Windows-exported CSV files convert cleanly.