Code & Text Tools

Work with text and code more efficiently using these free browser-based tools. Test and debug regular expressions with real-time pattern matching and capture group highlighting, compare two texts side by side with a visual diff checker, write and preview markdown with live HTML output, convert strings between camelCase, snake_case, kebab-case and other naming conventions, translate complex regex patterns into plain English, and escape or unescape strings for JSON, HTML, JavaScript and more — all running entirely client-side with no server calls and no signup required.

9 Code & Text Tools

Regex Tester & Debugger

Test regular expressions with real-time matching and capture group highlighting.

Popular

Text Diff Checker

Compare two texts side by side. Highlights additions, deletions and changes.

Markdown Editor & Preview

Write markdown with live preview. Convert to HTML. GFM tables and code blocks.

Regex Explainer

Translate regular expressions to plain English. Color-coded token breakdown.

String Case Converter

Convert between camelCase, snake_case, kebab-case, PascalCase and 8 more formats.

String Escape & Unescape

Escape and unescape strings for JSON, HTML, JavaScript, URL, CSV and SQL.

Character / String Length Counter

Live char, word, line, UTF-8 byte + tweet/SMS limits.

New

Word / Rich Text to Markdown

Convert pasted Word or HTML content to clean Markdown.

New

AI Token Counter

Estimate GPT / Claude tokens and cost for any prompt.

New

Which code & text tool should you use?

Code and text tools cover the day-to-day grind: testing a regex you'll never remember, comparing two configs, escaping strings for JSON or HTML, counting tokens before sending a prompt to GPT or Claude. The right choice depends on the format you're wrestling with and whether you need deep analysis (regex explainer) or a quick transform (case converter).

Test and debug a regex pattern with live highlighting and capture groups (JS flavor) — use Regex Tester & Debugger.
Translate a regex to plain English when inheriting unfamiliar patterns — use Regex Explainer.
Compare two text blobs side by side (configs, log diffs, JSON responses) — use Text Diff Checker.
Write/preview Markdown with GitHub-flavored tables and code blocks — use Markdown Editor & Preview.
Convert pasted Word/Google Docs content to clean Markdown — use Word to Markdown Converter.
Convert variable names between camelCase, snake_case, kebab-case, PascalCase — use String Case Converter.
Escape strings for JSON, HTML, JavaScript, URL, CSV, or SQL — use String Escape & Unescape.
Count characters, words, lines, bytes for tweet limits, SMS, OG titles — use Character Counter.
Estimate AI API costs before sending a prompt to GPT/Claude — use AI Token Counter. Catches expensive prompts early.

Common code & text mistakes to avoid

Greedy regex that matches too much. .* grabs everything to the end of line. Use .*? (lazy) or a more specific character class.
Forgetting to escape the dot in regex. . matches any character — use \. when you mean a literal period (e.g. matching example\.com).
Diffing two files that have different line endings. CRLF vs LF causes every line to show as changed. Normalize line endings first.
Mixing escape contexts. JSON-escaping " as \" then re-encoding for HTML produces double-escaped junk. Encode once, in the final destination format.
Trusting the 4-chars-per-token heuristic for non-English. CJK, code, and emojis can be 1 char per token or worse. Always count tokens in the actual tokenizer for cost-sensitive prompts.
Counting characters for Twitter/X without weighting URLs. URLs count as 23 chars regardless of length. Use a counter that knows the rules.

Frequently Asked Questions

Use the Regex Tester & Debugger to paste your pattern and test string, then see matches highlighted in real time. The tool displays each match, capture group, and index position instantly — no code, no compilation, no server round-trips. You can toggle flags like global, case-insensitive, and multiline to experiment with different matching behaviors. If a pattern is too complex to read, the Regex Explainer breaks it into color-coded tokens with plain-English descriptions so you can understand exactly what each part does.

The String Case Converter supports over ten common naming conventions used in software development, including camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, kebab-case, dot.case, Title Case, UPPERCASE, lowercase, and more. Simply paste your identifier or sentence and the tool instantly generates every format, making it easy to switch between coding styles when moving between languages or frameworks — for example, converting a JavaScript camelCase variable name to a Python snake_case equivalent.

String escaping is necessary whenever you embed user input or special characters inside a structured format. For example, JSON requires backslash escaping for quotes and control characters, HTML requires entity encoding for angle brackets and ampersands to prevent XSS, and SQL uses escaping to guard against injection attacks. The String Escape & Unescape tool handles all of these formats — paste your raw string, select the target format (JSON, HTML, JavaScript, URL, CSV, or SQL), and get a correctly escaped result you can safely embed in your code or data.

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