Free Cookie Converter & Formatter – Convert Cookies (Netscape ⇄ JSON ⇄ TXT)

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Need to convert browser cookies between Netscape, JSON, and TXT formats? Use our Cookie Converter for fast, reliable conversion with examples and format help.

This guide explains cookie formats (Netscape, JSON, TXT), how to convert between them safely, common errors, and quick validation tips.

TXT-style cookie lists are simple name=value pairs or custom delimited rows. Our tool handles these variants and maps them to Netscape or JSON as needed.

Exporting cookies from browser tools often yields Netscape-format files but many scripts require JSON. Converting manually is error-prone. The Cookie Converter automates format mapping and fixes common issues.

Supported Input & Output Formats

  • Input size: supports small-to-medium cookie files (single file up to several MB)
  • Fields required for JSON conversion: name and value; optional: domain, path, expires, secure
  • For Netscape output: domain, path, secure flag, expiry are included where available
  • Tool trims whitespace and fixes common delimiter issues automatically

Note: Always validate the converted file in your target tool. The converter aims to preserve essential fields but some custom tools may expect extra fields.

  • Instant conversion between Netscape, JSON, and TXT cookie formats
  • Client-side processing option (where supported) for privacy
  • Automatic field mapping and validation
  • Example inputs shown to reduce user errors
  • No signup required and minimal UI for quick workflows

The process is simple and works on mobile and desktop. Use the converter on our website to convert or download cookie files in your desired format.

Step-by-Step Conversion Guide

  1. Paste Sample: If you don’t have a file, paste a small sample of cookie lines or JSON array.
  2. Fix Issues: Use the validation hints to fix missing fields or encoding problems.
  3. Export: Export the converted result or copy it to clipboard for quick use.
  4. Load Into Script: Use the converted cookies in your automation or browser tool.
  5. Repeat: Repeat for other formats as needed.
  • Export cookies from browser devtools or an extension in Netscape (cookies.txt) or JSON format.
  • Open the file in a text editor to ensure it has cookie name=value pairs or valid JSON array.
  • If using JSON, ensure each cookie object has at least `name` and `value` fields.
  • Remove any extra comments or non-cookie lines before conversion.
Common Error Solution
Incorrect expiry format Convert expiry to Unix timestamp or remove if not needed
Missing name/value field Ensure each cookie has `name` and `value`
Delimiter mismatch in TXT Use standard name=value with one cookie per line
Extra comment lines in cookies.txt Remove comment lines before converting
Encoding issues Ensure UTF-8 encoding before conversion
Invalid JSON structure Fix JSON syntax or paste a valid JSON array
  • Exported Cookie Files: Use browser or extension exports (cookies.txt or JSON) for accuracy.
  • Programmatic JSON: Ensure your JSON objects have correct fields before converting.
  • Best Practice: Always validate converted output in a sandboxed environment before production use.
  • Preview converted output before downloading
  • Test with a small sample cookie file first
  • Keep backups of originals before converting
  • Use UTF-8 encoding to prevent character corruption
  • Validate domain/path fields if sessions fail after import

Final Checklist Before Using Converted Cookies

  • ✓ Input format correctly detected
  • ✓ Output format chosen (Netscape / JSON / TXT)
  • ✓ Name and value fields preserved
  • ✓ Domain and path fields present if required
  • ✓ Encoding: UTF-8
  • ✓ Test in a non-production environment first

Frequently Asked Questions

What input formats does the cookie converter accept?

It accepts Netscape cookies.txt, JSON array cookie exports, and simple name=value TXT lists. The tool auto-detects the format.

Is my cookie data stored on your servers?

We process data client-side where possible. If server-side conversion runs, we do not permanently store files and remove them after processing. Check the tool UI for the current behaviour.

Can I convert large cookie files?

Yes for most small-to-medium files. For very large exports, try splitting into smaller files to ensure smooth processing.

Will secure flags and expiry dates be preserved?

The tool preserves secure, expiry, domain, and path fields when available in the input.

Do I need to sign in to use the converter?

No, the basic conversion is free and doesn’t require an account.