Handy Dev Tools
Simple online tools for everyday tasks.

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    Base64 Encoder/Decoder
    Markdown to HTML
    HTML to Markdown
    URL Encoder/Decoder
    Unicode Escape Converter
    Unicode Encode/Decode
    SQL Formatter
    SQL Splitter
    JSON Formatter
    XML Formatter
    YAML Formatter
    GraphQL Formatter
    JSON to YAML Conversion
    YAML to JSON Conversion
    JSON to TOML Conversion
    TOML to JSON Conversion
    HTML Entity Encode/Decode
    TOML to YAML Conversion
    YAML to TOML Conversion
    CSV to SQL INSERT Conversion
    Markdown Table Generator
    JSON to XML Conversion
    XML to JSON Conversion
    UUID Generator
    ULID Generator
    Password Generator
    Hash Generator
    Lorem Ipsum Generator
    Lorem Picsum Image URL Generator
    Test Data Generator Tool
    QR Code Generator
    S3 Path Parser & Converter
    IP Address Calculator
    Subnet Split
    Subnet Consolidation
    CloudFront Signed URL Generator
    RDS Connection String Generator
    Coordinate Format Converter
    Geo Format Converter
    JWT Decoder & Parser
    Basic Auth
    Password Strength Analyzer
    Credit Card Validator
    RSA Key Pair Generator
    Case Conversion
    Romaji Conversion
    Roman Numeral Conversion
    Phonetic Code Conversion
    Character Counter
    Text Diff
    HTML Tag Remover
    Regex Tester
    Color Conversion
    Dice Roll
    Crontab generator
    Crontab parser
    Emoji Picker
    DateTime Converter
    HTTP Status Code Search
    Port Number Search
    MIME Type Lookup
    Base64 File Converter
    Image Base64 Encode/Decode
    JSON to XML Conversion
    XML to JSON Conversion
    User-Agent Parser
    URL Parser
    OGP Checker
    Commit Message Generator
    Chmod Calculator
    Terminal GIF Generator
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About Handy Web Tools

Handy Web Tools is a collection of simple online tools to streamline everyday development tasks.

All tools run in your browser and do not send data to external servers. You can use them safely while protecting your privacy.

Key Features

  • All processing runs in your browser, making it fast and secure
  • Privacy is protected as data is not sent to external servers
  • Supports both Japanese and English
  • Dark mode and light mode can be switched

Available Tools

We provide various development tools including UUID/ULID generation, Base64/URL encoding/decoding, color conversion, case conversion, romaji conversion, JSON/XML/YAML/SQL formatting, dice rolling, phonetic code conversion, password generation, and cron expression builder/parser.