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Tools starting with J

24 free online tools on AltFTool start with J, listed alphabetically. Every one is free, needs no sign-up and runs in your browser.

  • Jaccard Similarity Calculator

    Compare two texts as token sets and get the Jaccard index, distance, Dice, overlap and cosine coefficients.

    Calculators
  • JavaScript Tools

    Format, minify, and inspect JavaScript snippets locally.

    Developer
  • JDBC URL Builder

    Generate correct JDBC connection URLs for PostgreSQL, MySQL, Oracle, SQL Server, H2 and SQLite with driver-specific syntax.

    Developer
  • Job Board Profile Cleanup Guide

    Scan pasted résumé text for personal data that should not sit on a public job portal — government IDs, phone, address, date of birth and more — get an exposure score, and copy a redacted version.

    Security & Privacy
  • Job Offer Comparison Tool

    Compare multiple job offers side-by-side with intelligent scoring, financial breakdown, and recommendations to find the best opportunity.

    Productivity
  • Job Scam Deposit Checker

    Review a job offer locally for candidate-payment, money-mule, contact mismatch, compensation, urgency, and identity-pressure signals.

    Security & Privacy
  • Join Photo & Signature

    Merge photo and signature into a single image. Perfect for online applications (UPSC, bank, academic exams) requiring specific layout sizes and file KB limits.

    Image & Video
  • Joining Formalities Checklist

    Phase-wise checklist for medical exam, police verification, attestation forms and day-one joining paperwork.

    Productivity
  • Joke Generator

    Generate random jokes from multiple categories with favorites, search, and export options.

    Lifestyle
  • JS Beautifier

    Format, beautify, and clean minified or messy JavaScript code with options to adjust tab indentation size and copy output.

    Developer
  • JSON Compare

    Compare two JSON files, URL payloads, or text inputs side-by-side with semantic difference highlighting.

    Developer
  • JSON Editor

    Validate, format, minify, and convert JSON snippets.

    Developer
  • JSON Flatten Unflatten Tool

    Flatten nested JSON into dot-notation keys and rebuild the nested structure, with bracket or dot array styles.

    Converters
  • JSON Formatting

    Regular formatted display of JSON, plus automatic formatting/conversion for API interface testing (GET, POST, POST-JSON).

    Developer
  • JSON Mutual Conversion Postman Parameters Tool

    Convert JSON to Postman query params, form-data, x-www-form-urlencoded bodies, raw JSON, dynamic headers, and cURL with real-time two-way parsing.

    Developer
  • JSON Parser

    Parse JSON data and display it in a readable format

    Developer
  • JSON Relationship Mapper

    Map nested JSON into paths, inferred relationships, references, and structure metrics locally in your browser.

    Developer
  • JSON to Excel/CSV Converter

    Convert pasted JSON or uploaded JSON files into clean CSV and Excel-ready spreadsheet downloads.

    Developer
  • JSON To Go Struct Generator

    Generate production-ready Go structs from JSON with nested objects, arrays, nullable fields, JSON tags, copy, download, and local history.

    Developer
  • JSON to TOML Converter

    Convert JSON into readable TOML with proper [table] sections, [[array of table]] syntax and safely quoted keys.

    Converters
  • JSON to TypeScript

    Convert JSON objects recursively into type-safe TypeScript interfaces or type statements with formatting options.

    Developer
  • JSON to YAML Converter

    Convert JSON objects and arrays into readable YAML.

    Developer
  • Jump Code Generator

    Generate real anchor, smooth scroll, route navigation, button jump, and reusable navigation snippets instantly.

    Developer
  • JWT Decoder

    Decode JWT header and payload claims instantly in the browser.

    Developer