CSV to JSON Conversion: Complete Guide
Convert CSV to JSON with auto-delimiter detection, table view, and export to JSON, SQL, or Markdown. Best practices, common pitfalls, and how to use the CSV Viewer tool.
📊 CSV to JSON: From Spreadsheets to APIs in Seconds
CSV is everywhere—exports from Excel, Google Sheets, databases, and surveys. JSON is what most APIs and modern apps expect. Converting between them used to mean scripts or manual copy-paste. This guide shows you how to convert CSV to JSON quickly with auto-delimiter detection, table view, and multiple export options using our free CSV Viewer tool.
Why Convert CSV to JSON?
CSV is great for spreadsheets and exports; JSON is the lingua franca for APIs and front-end data. Converting CSV to JSON helps when:
🔌APIs & App Integration
- •Feed API payloads or seed data from spreadsheet exports
- •Use JSON in JavaScript/TypeScript without parsing CSV by hand
- •Match the format your backend or frontend expects
📁Data Portability & Analysis
- •Turn survey or DB exports into structured JSON for tools and scripts
- •Export to SQL INSERTs, Markdown tables, or TypeScript types from the same data
- •Preview and clean data in a table before committing to JSON
Using the CSV Viewer Tool
Our CSV Viewer turns pasted or uploaded CSV into a table, then lets you export to JSON and other formats. Step by step:
1Paste or Upload CSV
Paste CSV from Excel, Google Sheets, or a file. You can also upload a .csv or .tsv file. The tool auto-detects the delimiter (comma, semicolon, tab, pipe) so you usually don't need to change anything.
💡 Tip: First row is treated as headers and becomes the keys in the JSON objects. If your CSV has no header row, add one or the first data row will be used as keys.
2View & Edit in Table
Data appears in a sortable, filterable table. Use it to spot issues before exporting:
- →Sort: Click column headers to sort
- →Filter: Use search to narrow rows
- →Edit: Fix values directly in the table if needed
3Export to JSON or Other Formats
Choose how you want the output: JSON (array of objects, one per row), SQL INSERT statements, Markdown table, or TypeScript type definitions. Copy or download. JSON is ideal for APIs and app state; SQL for database seeding; Markdown for docs.
Auto-Delimiter Detection
CSV isn't always comma-separated. The tool detects the delimiter automatically:
| Delimiter | Common use |
|---|---|
| Comma (,) | Default in US/UK; Excel CSV export |
| Semicolon (;) | European locales (comma as decimal) |
| Tab | TSV; clipboard from spreadsheets |
| Pipe (|) | Legacy and some DB exports |
If detection is wrong, you can usually override the delimiter in the tool so the columns line up correctly.
Export Options
One dataset, multiple outputs:
- JSON — Array of objects; each row becomes one object, headers = keys. Perfect for APIs and front-end state.
- SQL — INSERT statements so you can seed a database from the same CSV.
- Markdown — Table syntax for docs, READMEs, or static sites.
- TypeScript — Type definitions inferred from the data so you can type your JSON in code.
Best Practices
Get reliable CSV → JSON conversion every time:
📏Consistent Headers & Delimiter
Use a clear header row with unique column names (no duplicates). Stick to one delimiter in the whole file. Mixed delimiters or missing headers lead to wrong keys or columns.
🔤Quoting & Special Characters
If a cell contains commas, newlines, or quotes, it should be wrapped in double quotes; internal quotes escaped as "". Most exporters do this automatically. When pasting from Excel, watch for unquoted commas inside cells—they can split one column into two.
🔢Data Types in JSON
CSV has no types—everything is text. In JSON, numbers and booleans are native. The converter typically keeps values as strings; if your API expects numbers or booleans, you may need a follow-up step (e.g. in code or with the JSON Formatter) to coerce types. Empty cells often become empty strings or you can treat them as null in your app.
Common Pitfalls & How to Avoid Them
Avoid these CSV → JSON mistakes:
❌Wrong Delimiter
If your CSV uses semicolons (e.g. European Excel) and the tool assumes comma, every row will look like one column. Check the table preview: if you see one huge cell per row, switch the delimiter or fix the source export.
⚠️Commas Inside Unquoted Cells
Values like Smith, John without quotes can be split into two columns. Re-export from your spreadsheet with "Quote all text" or wrap such fields in double quotes before pasting.
📄Encoding & BOM
UTF-8 is standard for JSON. If your CSV is Excel-exported with a BOM or another encoding, the first column name might show a stray character. Save as UTF-8 without BOM, or remove the BOM in a text editor, then re-paste.
Pro Tips
Work faster with the CSV Viewer and related tools:
📋Paste From Excel or Sheets
Copy a range from Excel or Google Sheets and paste into the CSV Viewer. The tab character is often used for clipboard data; the tool will detect it and show a proper table. Then export to JSON for APIs or config.
🔗Format JSON After Export
Export to JSON, then paste the result into the JSON Formatter to pretty-print, validate, or edit. Use JSON Diff to compare two CSV exports (e.g. before/after a data change).
✅ Convert CSV to JSON in Seconds
Use our CSV Viewer tool to paste or upload CSV, auto-detect delimiter, view and edit in a table, and export to JSON, SQL, Markdown, or TypeScript. Free, no sign-up, and runs in your browser. Then format or diff the JSON with our other data tools.
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