Category
Convert
Spreadsheet Column Converter
Convert between spreadsheet column letters and numbers — A=1, Z=26, AA=27, BC=55 — and between A1 and R1C1 cell notation.
JS Object ↔ JSON
Convert a JavaScript object literal (`{name: 'Alice'}`) to strict JSON — or strict JSON back into a tidy JS literal with unquoted keys.
JSON → SQL INSERT
Turn a JSON array of objects into INSERT statements — PostgreSQL, MySQL, SQLite, or ANSI quoting, with an optional ON CONFLICT upsert tail.
CSV ↔ TSV ↔ Pipe Converter
Switch delimited text between CSV, TSV, pipe, and semicolon — with proper RFC-4180-style quoting and auto-detection.
Subtitle Time Shifter
Paste an SRT or WebVTT file, type an offset in seconds, and get every cue shifted forward or backward.
JSON ↔ XML Converter
Convert between JSON and XML in both directions with configurable indent. Attributes use the `@_` prefix on the JSON side.
GPS Coordinates Converter
Convert latitude/longitude between decimal degrees, DMS (40°42'46"N), and DMM (40°42.7666'N). Generate Google Maps and geo: URIs.
Ohm's Law Calculator
Solve V, I, R, P from any two known values. V=IR, P=VI, P=V²/R, P=I²R — pick which pair you have, get the other two instantly.
Byte Size Converter (KB / KiB / MB / MiB / ...)
Convert between decimal (KB, MB, GB — SI base 1000) and binary (KiB, MiB, GiB — IEC base 1024) byte units, plus bits.
Resistor Color Code Calculator
Decode 4/5/6-band axial resistors into ohm value with tolerance — interactive color picker, gold/silver multipliers and tolerances supported.
HTML → Markdown Converter
Convert HTML to clean Markdown — headings, lists, links, tables, code blocks all preserved. Useful for migrating CMS content or scraping articles.
CSV → HTML / Markdown / JSON Table
Convert CSV to an HTML `<table>`, a Markdown table, or a JSON array of objects — auto-detects the delimiter.
Markdown Table of Contents Generator
Generate a `[text](#anchor)` TOC from Markdown headings — bullet, numbered, or HTML output with GitHub/GitLab/simple slug styles.
Markdown → Plain Text
Strip all Markdown formatting and keep readable plain text — useful for previews, summaries, email, character counts.
Aspect Ratio Calculator
Convert between width × height and aspect ratio (16:9, 4:3, 21:9, …) — fit any ratio inside a container.
CSV → SQL INSERT Generator
Convert CSV / TSV rows into SQL INSERT statements with table name, dialect quoting, type inference, and multi-row mode.
Number to Words
Spell out any number in English, Korean, or Japanese — for cheques, contracts, or just clarity.
CSS Unit Converter
Convert between px, rem, em, pt, vw, vh, and % using your own base font size and viewport.
JSON ↔ YAML Converter
Convert JSON to YAML or YAML to JSON — pick the indent and copy the result.
Data Size Converter
Convert between bytes, KB, MB, GB, TB — in decimal (1000) or binary (1024).
Roman Numeral Converter
Convert between Arabic numbers and Roman numerals from 1 to 3999.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal.
INI ↔ JSON Converter
Round-trip between INI-style config files and JSON — supports sections, dotted nesting, comments, and value type inference.
Unit Converter
Convert length, weight, temperature, area, volume, speed, and time.