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JSON、Base64、ハッシュ、エンコード、QR、ネットワーク、テキストなど — すべてブラウザ内で処理。アカウント不要。
カテゴリ別に閲覧:テキスト、URL、HTML、CSS、JSON、CSV、データベース、暗号、YAML など。
DB URL の解析、ランダム文字列、Base32/Base58/Base64、SHA・HMAC、bcrypt、QR、IPv4 CIDR など — ローカルで動作。
テキスト
Encoding, hashing, UUIDs, timestamps — string and digest helpers.
テキスト
Case converter
lower, UPPER, camelCase, PascalCase, snake_case, CONSTANT_CASE, Train-Case.
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HEX to text
Decode hex (with or without separators) back to UTF-8 text.
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Line sorter
Sort, reverse, shuffle lines; optional line numbers — all client-side.
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Lorem ipsum generator
Generate placeholder paragraphs with adjustable length.
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Text to HEX
UTF-8 bytes to space-delimited hex.
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Unix timestamp converter
Convert Unix seconds or milliseconds ↔ ISO 8601 dates in local and UTC.
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UUID generator
Generate RFC 4122 v4 UUIDs with one click — copy individually or all at once.
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Whitespace remover
Trim lines, collapse spaces, or strip all whitespace.
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Word counter
Count words, characters, and lines as you type — Unicode-aware.
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URL
Percent-encoding for queries, paths, and components.
URL
Slug generator
SEO-friendly URL slugs from titles — lowercase, hyphenated.
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URL decoder
Decode percent-encoded strings to readable text.
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URL encode / decode
Percent-encode or decode query strings and path components safely in the browser.
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URL encoder
Percent-encode text for safe use in URLs and query strings.
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URL parser
Inspect scheme, host, path, query, and hash with the URL API.
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HTML
Markup utilities (expand this group as you ship tools).
HTML
HTML decoder
Decode HTML entities back to characters.
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HTML encoder
Encode text to numeric / named HTML entities.
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HTML escape
Escape &, <, >, quotes for safe embedding in HTML.
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HTML formatter
Pretty-print HTML with js-beautify for readability.
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HTML minifier
Remove extra whitespace and shrink HTML for production.
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HTML stripper
Remove tags and keep text (best-effort).
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HTML unescape
Unescape common HTML entities.
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HTML validator
Well-formedness check (DOMParser) — not a full W3C nu validator.
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Markdown
Markdown helpers (expand this group as you ship tools).
CSS
Styles, shadows, and SVG → CSS for production.
CSS
CSS beautifier
Pretty-print CSS stylesheets.
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CSS box-shadow
Live preview for offset, blur, spread, and color — copy the value in one click.
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CSS minifier
Minify CSS with clean-css.
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CSS validator
Basic brace/bracket balance and structure hints — not full W3C.
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Shape divider generator
Create SVG wave, curve, tilt, and zigzag dividers for sections — copy SVG or CSS.
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SVG → CSS background
Turn inline SVG into a data URL and copy-ready background-image CSS.
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SVG generators
Browse SVG utilities: CSS background converter and shape divider generator — all client-side.
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JavaScript
JS-focused utilities (expand this group as you ship tools).
JavaScript
Code playground
Monaco IDE: run JavaScript, TypeScript, Python, Java, C++, Go in a remote sandbox; preview HTML locally. Shortcuts, console, starter templates.
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JavaScript beautifier
Pretty-print JavaScript with js-beautify.
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JavaScript escape
Escape a string for use inside JavaScript quotes.
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JavaScript minifier
Minify JS with terser (may fail on invalid syntax).
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JavaScript unescape
Unescape JavaScript string escapes.
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JSON
Format JSON, inspect JWTs — no server round-trip.
JSON
JSON escape
Escape a string for embedding in JSON.
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JSON formatter & validator
Format, minify, and validate JSON — fix payloads before APIs or configs.
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JSON minifier
Remove whitespace from JSON — compact one-liner.
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JSON unescape
Unescape JSON string escapes.
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JSON validator
Validate JSON and show parse errors with position.
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JWT decoder
Inspect header and payload (Base64URL). Read-only — does not verify signatures.
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XML
XML utilities (expand this group as you ship tools).
XML
JSON to XML
Convert JSON to a simple XML document.
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XML decoder
Decode XML entities.
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XML encoder
Encode special characters for XML text nodes.
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XML escape
Escape &, <, >, quotes for XML.
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XML formatter
Pretty-print XML with indentation.
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XML minifier
Collapse whitespace in XML.
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XML to JSON
Convert XML to JSON (fast-xml-parser).
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XML unescape
Unescape XML entities.
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XML validator
Parse XML and report errors (DOMParser).
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YAML
YAML utilities (expand this group as you ship tools).
CSV
Convert and export tabular data.
PHP
PHP helpers (expand this group as you ship tools).
データベース
Parse connection strings and inspect host, port, and database name.
データベース
Database URL parser
Split PostgreSQL, MySQL, MongoDB, Redis, and other connection URLs into scheme, host, port, user, and database.
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SQL escape
Escape single quotes for SQL string literals.
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SQL formatter
Pretty-print SQL with sql-formatter.
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SQL minifier
Strip SQL comments and collapse whitespace.
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ランダム
Secure random strings and values for tokens and test data.
ランダム
Passphrase generator
Random word-style passphrases from a word list.
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Password generator
Cryptographically random passwords — length and charset.
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PIN generator
Numeric PINs with secure randomness.
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Random string generator
Generate cryptographically random strings — length, charset, and one-click copy.
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Base32
RFC 4648 Base32 encode and decode in the browser.
Base32
Base32 decoder
Decode Base32 to UTF-8 text.
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Base32 encode / decode
RFC 4648 Base32 for encoded identifiers, OTP secrets, and text-safe binary.
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Base32 encoder
Encode UTF-8 text to RFC 4648 Base32.
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Base32 to HEX
Decode Base32 to hex string.
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HEX to Base32
Encode hex bytes as Base32.
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Base58
Bitcoin-style Base58 for compact binary-safe text.
Base58
Base58 decoder
Decode Base58 to UTF-8.
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Base58 encode / decode
Bitcoin-style Base58 — compact, avoids ambiguous characters (0, O, I, l).
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Base58 encoder
Encode UTF-8 bytes as Base58.
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Base58 to HEX
Decode Base58 to hex.
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HEX to Base58
Encode hex as Base58.
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Base64
Standard Base64 for UTF-8 text, APIs, and debugging.
Base64
Base64 decoder
Decode Base64 to UTF-8 text.
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Base64 encode / decode
Encode or decode Base64 for UTF-8 text — handy for APIs, tokens, and debugging.
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Base64 encoder
Encode UTF-8 text to Base64.
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Base64 to HEX
Decode Base64 to hex bytes.
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Base64 to image
Render a data URL / raw Base64 image in the browser.
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HEX to Base64
Encode hex as Base64.
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Image to Base64
Read a local image file to Base64 data URL.
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ハッシュ
SHA and other digests with Web Crypto — client-side only.
ハッシュ
MD5 hash generator
MD5 digest (crypto-js) — not for security.
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RIPEMD-160 hash generator
RIPEMD-160 digest.
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SHA hash generator
Compute SHA-256, SHA-384, or SHA-512 digests of any text — Web Crypto, client-side only.
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SHA-1 hash generator
SHA-1 digest — legacy interoperability.
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SHA-224 hash generator
SHA-224 digest.
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SHA-256 hash generator
SHA-256 digest.
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SHA-3 hash generator
SHA3-256 digest (crypto-js).
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SHA-384 hash generator
SHA-384 digest.
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SHA-512 hash generator
SHA-512 digest.
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HMAC
Keyed hashes for signatures and API authentication.
HMAC
HMAC generator
Compute HMAC-SHA-256/384/512 hex for a secret and message — useful for webhooks and APIs.
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MD5 HMAC generator
HMAC-MD5 hex.
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RIPEMD-160 HMAC generator
HMAC-RIPEMD160 hex.
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SHA-1 HMAC generator
HMAC-SHA1 hex.
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SHA-224 HMAC generator
HMAC-SHA224 hex.
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SHA-256 HMAC generator
HMAC-SHA256 hex.
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SHA-3 HMAC generator
HMAC-SHA3 hex.
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SHA-384 HMAC generator
HMAC-SHA384 hex.
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SHA-512 HMAC generator
HMAC-SHA512 hex.
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bcrypt
Password hashing and comparison with bcrypt.
QRコード
Generate QR codes from text or URLs — download or copy.
ネットワーク
CIDR, subnets, and IPv4 addressing helpers.
チェックサム
CRC and lightweight integrity checks over UTF-8 bytes.
Merge PDFs and extract page ranges — all processing runs in your browser.
Pastebin
Scratch pad and shareable links — everything stays in the browser or the URL.