JSON to CSV Converter

Convert JSON data to CSV format and vice versa. Flatten nested objects and export to Excel.

Updated Dec 06, 2025

JSON

Loading editor…

CSV

Data pipelines

Flatten JSON into trustworthy CSV files

APIs speak JSON, but analysts and BI tools still rely on CSV. The JSON to CSV Converter unwraps deeply nested objects, renames columns, and exports tabular data that behaves politely in Excel, Google Sheets, or warehouse loaders. Everything runs locally, so sensitive payloads never leave your browser.

Keep columns predictable

Drop in a sample response or paste a full production payload. The converter scans every object, builds a stable schema, and auto-fills missing fields with empty strings so spreadsheets do not shift columns as new keys appear. You can manually hide noisy properties, rearrange columns, and preview updates in real time.

For arrays nested inside each row, the tool offers multiple flattening strategies. Join values with commas, explode arrays into repeated rows, or keep JSON blobs intact for audit trails. Clear previews ensure you understand the transformation before downloading a single byte.

Uniform headers
Column names are normalized with consistent casing to prevent formula breakage when imports span multiple days.
Type-aware formatting
Numbers remain numbers, timestamps stay ISO strings, and booleans are converted to explicit TRUE/FALSE text.

Accelerate reporting

Once your CSV looks right, export it instantly or copy the preview table into dashboards. Because conversion happens in-browser, you can run the process even when offline or on locked-down corporate machines.

Teams frequently pair the converter with downstream QA steps. After flattening, compare two CSV runs in the Diff Checker to confirm only expected rows changed, or feed the result into spreadsheet templates shared with stakeholders.

One-click download
Choose between UTF-8 CSV, TSV, or clipboard-friendly tables, depending on where the data goes next.
Schema documentation
Copy the generated column manifest into README files so teammates know exactly what each field represents.

Use cases we see daily

Ad-hoc API audits

Grab a response from Postman or the Curl Converter, flatten it, and hand it to finance or support teams without exposing your codebase.

Migration dry runs

Before importing data into CRM or billing tools, ensure the CSV matches their templates and character limits.

Analytics prototypes

Stand up quick pivot tables to validate hypotheses while your data engineers wire up permanent pipelines.

Version tracking

Archive daily exports alongside commit hashes so you can trace how schema tweaks affected downstream dashboards.

Next step

Diff two exports before you share

Open the Diff Checker to compare today’s CSV with last week’s snapshot. Visual highlights make it obvious which rows or columns changed, helping stakeholders trust the update.

Open Diff Checker

Popular combinations

Audit with Diff Checker
Compare JSON to CSV Converter output with previous revisions to avoid regressions.
Share via QR Code Generator
Turn sanitized payloads into QR codes for offline reviews.

Frequently asked questions

How does the conversion work?

The tool flattens your JSON structure into a table format. Keys become column headers, and values become rows. Nested objects are flattened using dot notation (e.g., 'user.address.city').

Can I convert CSV back to JSON?

Yes. This tool supports bidirectional conversion. You can paste CSV data to convert it back into a structured JSON array.

How are large files handled?

The converter is optimized for performance and can handle reasonably large datasets directly in your browser. However, extremely large files (hundreds of megabytes) might slow down the page.

Is my data private?

Yes. All conversion happens locally in your browser. We do not upload your data to any server.

How to use JSON to CSV Converter

Follow these four quick steps to transform data between ecosystems right inside your browser—no downloads, no accounts, and no data leaving the FreeTools.run sandbox.

Step 1: Load your source data
Paste text, drag a file, or start with our curated sample to understand how the converter workflow behaves with real inputs.
Step 2: Adjust tool options
Toggle presets, update formatting rules, or choose export preferences. All controls update in real time so you can preview the effect before committing.
Step 3: Review the live preview
Use the split-pane preview, inline validation, or diff output to confirm the transformation looks correct before you copy anything back into your project.
Step 4: Export or chain another tool
Copy the result, download a file, or jump into a related FreeTools.run utility (like Diff Checker or the QR Code Generator) to continue the workflow without leaving the browser.