CSV Toolkit is a free, privacy-first collection of browser-based CSV tools. Convert, format, validate, clean, split, sort, filter, and transform CSV files — all without uploading your data to any server. Tools include CSV to JSON Converter, CSV Validator, CSV Formatter, CSV Duplicate Remover, CSV Viewer, CSV Encoding Checker, CSV Splitter, CSV Sorter, CSV Cleaner, CSV Row Filter, and more. Everything runs in your browser. Your data never leaves your device.