Online Converter Tools

Quickly convert files, formats, and data with our smart converters.

Base64 To Image

Convert Base64 string into an image file instantly.

CSV To JSON

Easily transform CSV data into structured JSON.

Date To Julian

Convert a normal date to Julian date format.

Excel To JSON

Turn Excel sheets into clean JSON data.

Image To Base64

Encode your image to Base64 format easily.

Julian To Date

Convert Julian date values back to standard date.

JSON To CSV

Convert structured JSON into a CSV table format.

JSON To Excel

Easily export JSON data to Excel format.

Online File & Data Converter Tools

Welcome to TwinFishTech Converter Suite — a collection of powerful and free online tools to convert your data formats with just one click. Whether you need to convert images, Base64, CSV, Excel, or JSON, we make it fast, secure, and developer-friendly.

Our Popular Data Converter Tools

Explore a range of smart online converters built for developers, data analysts, and general users. Every tool is designed to simplify data handling and improve productivity.

Base64 to Image Converter: Instantly decode Base64 strings into downloadable image formats such as PNG or JPG.
Image to Base64 Converter: Easily encode image files into Base64 format for HTML, CSS, or JSON embedding.
CSV to JSON Converter: Convert CSV spreadsheets into clean JSON data structures for web applications.
JSON to CSV Converter: Transform complex JSON objects into simple CSV format for reporting or data import.
Excel to JSON Converter: Upload Excel (.xls, .xlsx) files and get structured JSON outputs instantly.
JSON to Excel Converter: Export JSON data into a formatted Excel spreadsheet with one click.
Date to Julian Converter: Quickly convert Gregorian calendar dates into Julian date numbers.
Julian to Date Converter: Decode Julian day values back to standard date format for human readability.

All TwinFishTech converters run completely in your browser — no file upload to external servers, ensuring speed, accuracy, and privacy.