Free Tools for Data Scientists
Essential tools for data scientists: convert data formats, test patterns, and transform datasets — all free, all private, all in your browser.
Data Conversion
JSON to CSV Converter
Convert API response JSON to CSV for import into pandas, R, or spreadsheet analysis
JSON Formatter
Explore and format nested JSON datasets to understand structure before writing parsers
Base64 Encode/Decode
Decode Base64-encoded data fields from APIs and database exports
Pattern Matching
Regex Tester
Build regex patterns for text extraction, data cleaning, and log parsing pipelines
Text Diff Checker
Compare data processing outputs before and after transformations to verify correctness
Utilities
Unix Timestamp Converter
Convert epoch timestamps in datasets to human-readable dates for time-series analysis
Word & Character Counter
Analyze text corpus statistics — word count, character distribution, and readability metrics
UUID Generator
Generate unique experiment IDs and sample identifiers for reproducible research
Common Workflows for Data Scientists
Convert API Data to Spreadsheet
Fetch JSON from a REST API, paste it into the JSON to CSV converter, and download a CSV ready for pandas.read_csv() or Excel import.
Build Data Cleaning Regex
Use the Regex Tester to create patterns that extract phone numbers, emails, dates, or custom formats from unstructured text data.
Explore Nested JSON Datasets
Paste large JSON responses into the Formatter to visualize nested structures, identify keys, and plan your data extraction logic.
Verify Data Pipeline Outputs
Use the Diff Checker to compare expected vs. actual outputs from ETL pipelines to catch transformation bugs.
Frequently Asked Questions
Can I convert large JSON files to CSV?
Yes. The converter handles files up to several MB entirely in your browser. For very large datasets, consider chunking the JSON first.
Is my data safe when using online tools?
Absolutely. All processing happens in your browser's JavaScript engine. No data is uploaded to servers — your datasets remain completely private.
Do these tools support Unicode and special characters?
Yes. All tools handle full UTF-8 including Unicode, emoji, CJK characters, and special symbols correctly.
Tools for Other Professions
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