Converters
Convert between units, formats, and data types instantly — everything runs locally.
Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal or any base from 2 to 64 — even very large ones. Free, in your browser.
ConvertersRoman Numeral Converter
Convert numbers to Roman numerals and back (1–3999) — instantly, in your browser, with malformed-numeral validation.
ConvertersUnit Converter
Convert cm to inches, kg to lbs, °C to °F, GiB to GB — 178 units across 23 categories, searchable by name, one click for the common pairs. In your browser.
ConvertersCoordinate Converter — WGS84, Korean TM (EPSG:5186), UTM
Convert between WGS84 lat/lon, Korean TM (EPSG:5185-5188), UTM-K 5179, UTM and legacy Bessel coordinates, with degrees to DMS and a map preview. Free.
ConvertersNumber to Words Converter
Convert any number into spelled-out words in English or Korean, from zero to the billions and beyond — runs 100% in your browser with no upload.
ConvertersJSON ⇄ TOML Converter
Convert JSON to TOML and TOML back to JSON, both directions, with clear error messages — 100% in your browser, no upload.
ConvertersTime Zone Converter
Convert a date and time from one time zone to another with the live UTC offset — runs 100% in your browser with no upload.
ConvertersCooking Measurement Converter
Convert recipe amounts between cups, tablespoons, teaspoons, millilitres and fluid ounces, or to grams for flour, sugar and butter — in your browser, no upload.
ConvertersFuel Economy Converter
Convert fuel economy between US MPG, UK MPG, km/L and L/100km instantly — runs 100% in your browser with no upload.
ConvertersCSV to JSON Converter
Convert CSV or TSV to JSON — objects, keyed, column arrays, JSON Lines or minified. Sort, skip, limit, 10 file encodings. In your browser, no upload.
ConvertersXML to JSON Converter
Convert XML to JSON in your browser — attributes, repeated tags, 5 spacing choices, optional root unwrap. Paste, open a file, or load a URL. No upload.
ConvertersBase32 & Base58 Encoder / Decoder
Encode and decode text with Base32 (RFC 4648) or Base58 (Bitcoin alphabet) — 100% in your browser, nothing uploaded.
ConvertersExcel to CSV / JSON Converter
Convert Excel .xlsx spreadsheets to CSV or JSON and back — 100% in your browser, no upload
ConvertersGzip, Zlib & Deflate Compressor
Compress or decompress text with gzip, zlib or raw DEFLATE, with base64 output and a live size ratio — 100% in your browser, no upload
ConvertersFile to Base64
Encode any file to a Base64 string or data: URI, and decode Base64 back to a downloadable file — 100% in your browser, no upload.
ConvertersCSV Transpose
Swap the rows and columns of a CSV or TSV table — 100% in your browser, no upload.
ConvertersQuoted-Printable Encoder / Decoder
Encode or decode MIME Quoted-Printable text and =?UTF-8?Q?…?= email headers — 100% in your browser, no upload
ConvertersCSV Validator
Find ragged rows, wrong column counts and empty cells in a CSV — 100% in your browser, no upload
ConvertersFile Splitter & Joiner
Split any file into fixed-size or N chunks and rejoin them — 100% in your browser, no upload
ConvertersCSV to TSV, XML & YAML Converter
Convert CSV or TSV to TSV, XML, or YAML — 100% in your browser, no upload.
ConvertersCharset Converter — Fix Mojibake
Fix mojibake — decode legacy code pages such as Windows-1252, ISO-8859, Shift_JIS, EUC-KR, GBK, Big5 and KOI8-R to Unicode. Free, no upload, in your browser.
ConvertersPHP Serialize ⇄ JSON Converter
Convert PHP serialize() output to JSON and JSON back to a serialized string — read the arrays and objects in sessions, cookies and cache. Free, no upload.
ConvertersZIP Maker & Extractor
Create a ZIP from your files, or unpack and peek inside any .zip, .jar or .docx — 100% in your browser, no upload
ConvertersAudio Converter
Convert audio to MP3, WAV, FLAC, AIFF, M4A or OGG in your browser, with trim, fade and normalise built in — no ffmpeg to install, no upload, no sign-up.
Two different kinds of conversion live here. Numbers and units — between measurement systems, number bases, Roman numerals, coordinate systems, and time as a decimal. Data between shapes — CSV to JSON and back, XML to JSON, Excel in and out, character encodings, Base32/Base58, quoted-printable, PHP serialize, gzip and deflate.
The CSV group is worth knowing about as a set, because a broken CSV is usually one of a few specific things. Validate tells you which row breaks and why. Transpose swaps rows and columns when a spreadsheet arrives the wrong way round. Convert to formats takes it to JSON, SQL, Markdown or HTML in one step.
If text arrives as ìƒì„ or ë°˜ rather than words, that is a character encoding mismatch rather than damage, and the charset converter is what recovers it — most often a file written as EUC-KR or Shift-JIS being read as UTF-8. The bytes are still correct; only the reading is wrong.