Developer Utilities
Free online developer utilities — code beautifier, SQL formatter, diff, keycode and ASCII reference, number base/IEEE 754/bitwise tools, LLM cost and token counters and AI text detection. All in your browser.
30 free developer utilities — all browser-based
Code Beautifier
Formats and indents messy HTML, CSS, or JavaScript code into a clean, readable style with configurable indent size..
SQL Formatter
Formats SQL queries for better readability and consistency. It automatically adjusts indentation, capitalizes keywords, and improves query structure..
Diff Tool
Compares two text inputs and highlights their differences. Useful for code reviews, debugging, and tracking changes between document versions..
Keycode Info & Inspector
Captures KeyboardEvent properties (key, code, keyCode, location, modifiers, and legacy which) in real time as keys are pressed, displaying the full event payload as a JSON snapshot, useful for implementing keyboard shortcuts, debugging key bindings in games and editors, building accessibility-friendly interactions, and verifying cross-browser keyCode differences between Chrome, Firefox, and Safari..
ASCII Table
A searchable reference of all 128 ASCII characters with their decimal, hexadecimal, octal, and binary codes, including control character names..
Number Base Converter
Converts integers between binary (base-2), octal (base-8), decimal (base-10), and hexadecimal (base-16), plus an arbitrary base up to 36, with live two-way conversion.
IEEE 754 Float Inspector
Decodes the bit-level representation of IEEE 754 single (32-bit) and double (64-bit) floating-point numbers using DataView, showing the sign, exponent, mantissa bits, biased exponent value, and the reconstructed decimal, plus special values (NaN, Infinity, subnormals), useful for understanding floating-point precision loss, debugging 0.1 + 0.2 surprises, and porting float logic between languages..
Bitwise Calculator
Performs bitwise operations (AND, OR, XOR, NOT, left/right shift) on arbitrary-precision integers using BigInt, with a live binary, octal, decimal, and hex breakdown of both operands and the result, plus signed and unsigned interpretations, useful for learning binary arithmetic, designing bit flags and bitmasks, and verifying low-level protocol and hardware register calculations..
Number Formatter
Numbers are converted to binary, octal, hexadecimal, or vice versa..
Number to Words Converter
Spells out whole and decimal numbers in US English short-scale form (thousands, millions, billions, trillions, quadrillions), handling negatives, commas, and decimal points.
Percentage Calculator
Calculates X% of Y, what percent X is of Y, and the percentage change between two numbers, all updating live..
Roman Numeral Converter
Converts numbers (1-3999) to Roman numerals and back, validating that the entered Roman numeral is in canonical form..
LLM API Cost Calculator
Estimates the per-request cost of a prompt across major LLM APIs.
Token Counter
Estimates the LLM token count of a prompt or text using the ~4 chars/token approximation, with character/word/line/byte stats and live context-window usage bars for GPT-4o, Claude, Gemini, Llama, and DeepSeek..
AI Text Detector
Estimates the AI-likelihood of pasted text from six in-browser statistical heuristics.
Text to Speech
Converts typed text into spoken audio using your browser's built-in voices, with adjustable rate and pitch.
Markdown Viewer
Renders Markdown files into a properly formatted preview. Supports headings, tables, code blocks, and more for an enhanced viewing experience..
Markdown to HTML
Converts Markdown into HTML source you can copy and embed, with both a raw HTML view and a sanitized live preview..
Markdown Table Generator
Converts pasted CSV or TSV (spreadsheet) data into a properly formatted Markdown table, with configurable column alignment..
Markdown Table Formatter
Formats and aligns GitHub-Flavored Markdown pipe tables, normalizing column padding, header separators, and cell trimming so tables render consistently across renderers, with optional left/center/right column alignment, useful for cleaning up hand-typed markdown tables in README files, docs sites, and Notion / Obsidian exports..
HTML to Markdown Converter
Converts pasted HTML into clean, readable Markdown (headings, lists, links, code blocks, tables, and emphasis preserved), useful for migrating content into wikis and README files, preparing AI prompts, and stripping formatting from rich-text sources..
HTML Minifier
Compresses HTML by stripping comments, collapsing whitespace, and removing gaps between adjacent tags.
HTML Sanitizer
Sanitizes untrusted HTML using DOMPurify with configurable allowed tags, attributes, and protocol schemes, stripping XSS payloads, event handlers, and javascript: URLs while preserving safe formatting, useful for previewing user-submitted HTML, testing CMS rich-text filters, and hardening email and chat message rendering against script injection..
Levenshtein Distance Calculator
Computes the Levenshtein edit distance between two strings.
HTML to JSX Converter
Converts HTML into JSX for React, renaming class to className and for to htmlFor, camelCasing hyphenated attributes and event handlers, turning inline style strings into style objects, self-closing void elements, converting HTML comments into JSX expression comments, and escaping braces in text, useful for pasting a design export or Bootstrap snippet into a component..
SQL DDL to TypeScript
Converts SQL CREATE TABLE statements into TypeScript interfaces, mapping SQL types to string, number, boolean, Date and Buffer across PostgreSQL, MySQL and SQLite spellings, marking nullable columns as optional or union with null, converting snake_case columns to camelCase properties, and turning table names into PascalCase interface names..
Byte Size Converter
Converts data sizes between bytes, decimal SI units (KB, MB, GB, TB, PB at 1000) and binary IEC units (KiB, MiB, GiB, TiB, PiB at 1024), plus bits, showing every unit at once so the 1000-versus-1024 discrepancy behind mismatched disk and RAM figures is visible, and accepting input written with or without a space..
SVG to JSX Converter
Converts an SVG into a React component, camelCasing hyphenated attributes such as stroke-width and clip-rule, renaming class to className, converting inline style strings into objects, optionally replacing hard-coded fill and stroke colors with currentColor and forwarding props, so an exported icon drops straight into a component library..
GraphQL Formatter
Formats and minifies GraphQL queries, mutations and SDL schemas with a purpose-built tokenizer that understands block strings, string escapes, comments, directives and variable definitions, normalizing indentation and argument spacing, and reporting unbalanced braces or parentheses with the line where the imbalance starts..
SQL IN Clause Generator
Turns a pasted list of values into a SQL IN clause, splitting on newlines, commas or tabs, detecting whether the values are numeric or need quoting, escaping embedded single quotes, removing duplicates and blanks, and chunking the output into several OR'd clauses so it stays under Oracle's 1000-item and SQL Server's parameter limits..
Formatting and comparing code
The Code Beautifier pretty-prints HTML, CSS, JS and JSON, and the SQL Formatter indents queries for readability.
The Diff tool highlights line-by-line changes between two text blocks.
Number and binary utilities
Convert between binary, octal, decimal and hex with the Number Base Converter, and inspect IEEE 754 float layouts bit-by-bit.
The Bitwise Calculator performs AND, OR, XOR, NOT and shifts on BigInt values.
LLM and AI helpers
Estimate token counts for prompts with the Token Counter and project API spend with the LLM Cost Calculator.
Frequently asked questions
Does the AI text detector send my text to a server?
No. It runs a local heuristic analysis of perplexity and burstiness entirely in the browser.