Free Online Text Tools for Developers

Text tools developers reach for daily

Text manipulation is one of the most frequent tasks in development — converting naming conventions between languages, comparing configuration files, stripping duplicates from exported lists, generating placeholder content for UI work. These tasks are simple enough that writing a dedicated script feels wasteful, but tedious enough to do manually. Browser-based text tools fill this gap.

Analysis tools

The Word and Character Counter goes beyond a simple count — it tracks words, characters with and without spaces, sentences, paragraphs, reading time, and keyword density. The keyword density section shows the top 10 most-used words with frequencies, useful for checking whether content is overusing a term or is missing a target keyword before publishing. The Word Frequency Analyser provides a complete ranked breakdown of every unique word in a text, which is useful for log analysis, translation quality checks, and content auditing.

Case and format conversion

The Text Case Converter converts between camelCase, PascalCase, snake_case, kebab-case, SCREAMING_SNAKE_CASE, Title Case, and Sentence case. Converting database column names to JavaScript camelCase, renaming a batch of CSS classes to kebab-case, or fixing the casing of a list of constants — all handled in one paste. The Slug Generator is a specialised version for URLs: it converts any title or phrase into a clean, URL-safe slug with configurable separators and bulk mode for processing multiple inputs at once.

Cleaning and deduplication

The Duplicate Line Remover strips repeated lines from any text block with options for case-sensitive or case-insensitive matching, whitespace trimming, and sorting the output after deduplication. Useful for cleaning exported lists, merging configuration files, and removing repeated log entries. The String Reverser reverses text character by character, word by word, or line by line — covering encoding checks, algorithm testing, and list reordering.

Diff and comparison

The Diff Checker compares two text blocks line by line using the Longest Common Subsequence algorithm. Additions are highlighted in green, removals in red, unchanged lines in grey. Both input panels include line number gutters that scroll in sync with the content. Useful for comparing configuration files, reviewing rewritten content, or checking what changed between two API responses without access to git.

Markdown tools

The Markdown Preview gives you a side-by-side editor with real-time rendered output. The parser supports all standard Markdown including tables, code blocks, and strikethrough, built without external dependencies. The Markdown to HTML converter produces clean HTML output you can paste directly into a page. The HTML to Markdown converter does the reverse — useful for migrating content from a CMS or legacy HTML pages to a Markdown-based system.

Privacy matters for text tools

Text you process in development tools often includes sensitive content: customer names, email addresses, internal copy before it is published, API error messages with internal paths, or configuration values. Every tool on this page processes text entirely in your browser. Nothing is sent to a server, nothing is logged, and nothing persists after you close the tab.