Convert

Convert between spreadsheet column letters and numbers — A=1, Z=26, AA=27, BC=55 — and between A1 and R1C1 cell notation.

Convert a JavaScript object literal (`{name: 'Alice'}`) to strict JSON — or strict JSON back into a tidy JS literal with unquoted keys.

Turn a JSON array of objects into INSERT statements — PostgreSQL, MySQL, SQLite, or ANSI quoting, with an optional ON CONFLICT upsert tail.

Switch delimited text between CSV, TSV, pipe, and semicolon — with proper RFC-4180-style quoting and auto-detection.

Paste an SRT or WebVTT file, type an offset in seconds, and get every cue shifted forward or backward.

Convert between JSON and XML in both directions with configurable indent. Attributes use the `@_` prefix on the JSON side.

Convert latitude/longitude between decimal degrees, DMS (40°42'46"N), and DMM (40°42.7666'N). Generate Google Maps and geo: URIs.

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.

Convert between decimal (KB, MB, GB — SI base 1000) and binary (KiB, MiB, GiB — IEC base 1024) byte units, plus bits.

Decode 4/5/6-band axial resistors into ohm value with tolerance — interactive color picker, gold/silver multipliers and tolerances supported.

Convert HTML to clean Markdown — headings, lists, links, tables, code blocks all preserved. Useful for migrating CMS content or scraping articles.

Convert CSV to an HTML `<table>`, a Markdown table, or a JSON array of objects — auto-detects the delimiter.

Generate a `[text](#anchor)` TOC from Markdown headings — bullet, numbered, or HTML output with GitHub/GitLab/simple slug styles.

Strip all Markdown formatting and keep readable plain text — useful for previews, summaries, email, character counts.

Convert between width × height and aspect ratio (16:9, 4:3, 21:9, …) — fit any ratio inside a container.

Convert CSV / TSV rows into SQL INSERT statements with table name, dialect quoting, type inference, and multi-row mode.

Spell out any number in English, Korean, or Japanese — for cheques, contracts, or just clarity.

Convert between px, rem, em, pt, vw, vh, and % using your own base font size and viewport.

Convert JSON to YAML or YAML to JSON — pick the indent and copy the result.

Convert between bytes, KB, MB, GB, TB — in decimal (1000) or binary (1024).

Convert between Arabic numbers and Roman numerals from 1 to 3999.

Convert any decimal into its closest fraction (with adjustable maximum denominator, including binary fractions for inch measurements), and any fraction back into decimal / percent. Includes side-by-side common-fraction and 1/16″ inch-fraction reference tables.

Convert shoe sizes between US, UK, EU, and Mondopoint (cm) for men's and women's footwear with the full chart visible.

Convert numbers between binary, octal, decimal, and hexadecimal.

Convert XML to JSON and back, with full attribute support, configurable attribute prefix and text key. Browser-native DOMParser handles namespaces, CDATA, comments.

Convert between latitude/longitude and geohash strings (Niemeyer 2008). Adjustable precision 1-12, with bounding box and 8 neighbor cells.

Browse ISO 216 A/B/C, US (Letter/Legal/Tabloid/ANSI), Japanese JIS-B, photo and envelope paper sizes — see millimeters, inches and pixel dimensions at any DPI, plus side-by-side size comparison.

Convert between decibels and linear ratios for either voltage/SPL (20·log) or power (10·log), sum multiple dB SPL sources logarithmically, and look up reference levels (dBV, dBu, dBm, dBFS, dB SPL, dBW, dBi) and common everyday loudness values.

Convert between American Wire Gauge (AWG), wire diameter (mm and inch), cross-section area (mm² and kcmil), British Standard Wire Gauge (SWG), resistance per km/1000ft for copper and aluminum, and NEC ampacity tables for chassis wiring and power transmission.

Two-way converter between running pace (min/km, min/mile) and speed (km/h, mph, m/s, knots) with race time projections for 100 m, 400 m, mile, 5K, 10K, half marathon, and marathon at the chosen pace.

Convert any angle between degrees, radians, gradians, turns, milliradians, arcminutes, arcseconds, and DMS — with live SVG preview and π-fraction recognition.

Convert between TOML (`Cargo.toml`, `pyproject.toml`, Hugo configs) and JSON — handles tables, array-of-tables, inline tables, typed scalars.

Round-trip between INI-style config files and JSON — supports sections, dotted nesting, comments, and value type inference.

Convert length, weight, temperature, area, volume, speed, and time.