Text & Writing Utilities
Browser-native utility tools that execute 100% locally on your computer. No user accounts, registration, or server-side communication.
Text Character Encoding Converter
You can mutually convert the character code of text and files to Shift_JIS, EUC-JP, UTF-8, etc., and decipher and repair garbled characters.
Regex Extractor
Extracts all strings that match regular expressions (emails, URLs, phone numbers, etc.) from text at once.
Ngram Analyzer
We aggregate and analyze the sequential appearance patterns (N-grams) of letters and words in sentences, as well as related words that tend to appear together with specific words (co-occurrence words).
Word Counter
In addition to the number of characters and lines, full-width/half-width discrimination, number of manuscript paper equivalents, etc. are counted in real time on the browser.
Secure Notepad
This is a local memo pad that automatically saves entered text so that data will not be lost even if you accidentally close the tab.
Text Diff Checker
Compares two sentences and highlights added parts (green) and deleted parts (red) by line, word, or character.
Duplicate Line Remover
Batch deletes duplicate lines from multiple lines of text and sorts and formats them in ascending order, descending order, length order, etc.
Case Converter
Convert text character formats at once, including uppercase/lowercase, camel, snake, full-width/half-width, hiragana/katakana, etc.
List Converter
Converts a comma-separated string (CSV-like data) to a list of line breaks, or vice versa, by adding quotes.
Text Replacer
Replace specific characters or strings in text at once using case sensitivity and regular expression patterns.
Csv Transposer
Preview the CSV data vertically (rows) and horizontally (columns) in table format, flip it, and re-output.
JSON XML Converter
Bidirectionally converts JSON format object data to XML tag structure or XML to JSON format.
Whitespace Trimmer
Remove or clean up extra spaces at the beginning and end of lines, consecutive spaces, and unnecessary line breaks in text at once.
Dummy Story Generator
Automatically generates English Lorem Ipsum and Japanese classical literature-style dummy sentences for web design comps and development verification.
User Agent Analyzer
Analyzes the User-Agent string sent by the browser and visualizes OS, browser, and device information.
Text Metrics Visualizer
This is a writing support tool that visualizes the length distribution of each paragraph/sentence of input text and the appearance ratio of punctuation marks (,.) in real time using a histogram.
JSON Csv Flattener
Converts complex JSON data and CSV data with nested structures by mutually flattening the hierarchy.
Morse Code Generator
We perform mutual conversion between Japanese (Japanese), alphanumeric characters (Roman) and Morse code, and perform pronunciation playback simulation using Web Audio API.
Text Obfuscator
As a countermeasure against automatic email collection spambots, email addresses and phone numbers are converted into HTML entity references and obfuscated JavaScript code.
Csv Column Editor
Sort the columns of the uploaded CSV file, rewrite the header, delete unnecessary columns, and extract row data conditionally.
Text Sorter
Automatically sorts multiple lines of text or list data in alphabetical order, numerical order, character length order, random order, etc.
JSON Schema Validator
Verify whether the input JSON data meets the requirements defined by JSON Schema (type, required items, value range, etc.).
Markdown HTML Converter
Converts Markdown (Markdown notation) documents and HTML code in both directions. Fully equipped with preview display function.
Text Splitter
Smartly divides and slices long sentences according to the 140 character limit and API limit of X (formerly Twitter).
Proofreading Tool
Detects and proofreads unnatural expressions in Japanese (double negatives, omitted words, redundant expressions, double words, etc.) and fluctuations in the spelling of okurikana.
Secure Client-Side Sandbox
All tools displayed in this category run locally in your browser sandbox. None of the inputs, file data, or processing logs are sent to any remote servers or APIs.
Text & Writing Utilities: Comprehensive Guide
Diff checking, encoding converters, deduplication, and regex extraction
Comparing contract drafts, sanitizing log files, repairing encoding issues, and extracting patterns from raw text are common daily tasks. Pasting unreleased drafts or confidential text into cloud-hosted tools creates serious compliance risks. ZeroTools processes text datasets locally, delivering high-speed analysis even on large multi-megabyte documents.
Safe Proofreading of Sensitive Drafts
Review legal contracts, embargoed press releases, and internal meeting minutes with zero leak exposure.
High-Performance Text Streaming
Optimized string processing algorithms handle tens of thousands of lines smoothly in local memory.
Universal Format Conversions
Easily switch between Markdown, HTML, CSV, JSON, and Unicode escape sequences.
1Granular Diff Comparison & Character Encoding Repair
Compare texts and source code with word-by-word and character-by-character visual diff highlights. Repair garbled CSV files (Shift_JIS ⇔ UTF-8) with automatic encoding detection directly in your browser.
2Deduplication, Sorting & Pattern Extraction
Clean large email lists and server logs with instant duplicate removal, natural sorting, and regular expression pattern extraction for URLs, IPs, and email addresses with no UI freezing.