Spectrum file converter

1. Drop the file on the page, or choose it. It is read in your browser.
2. Check the preview: axis units, the number of points and the metadata the file carries. A file with several spectra — a multi-subfile SPC, an NTUPLES JCAMP-DX page set or a CSV with several Y columns — lists them all.
3. Pick CSV, Excel, TSV, JCAMP-DX or JSON and download.

Reads: JCAMP-DX 4.24, 5.00 and 5.01 in AFFN and every compressed form (SQZ, DIF, DUP, PAC), link and compound files, every NTUPLES page including 2D NMR and LC-MS spectral series; Galactic SPC new (little- and big-endian) and old format, 16-bit or 32-bit, even or XY data, several subfiles; CSV, TSV, TXT and XY columns with a decimal point or comma. Files are decoded as UTF-8, UTF-16 or Windows-1252.

Writes: JCAMP-DX 5.01 with DIFDUP compression, 80 characters per line and the Y relay check the IUPAC recommendation asks for; CSV with a header row; an Excel workbook (.xlsx) with the data, the peak list and a metadata sheet; tab-separated text; JSON with arrays and metadata.

Damaged files: what is readable is converted; a truncated block, a wrong point count, a failed DIF relay check or a character that is not data is named with its line, and a cut short SPC subfile with its byte offset.

The Excel workbook stores numbers as numbers, so it opens correctly with any regional setting. For CSV, switch on the decimal comma if your Excel expects one: the file then uses semicolons between columns and commas in numbers.

AFFN writes every number in full. The ASDF forms replace digits with letters: SQZ folds the sign and first digit into one character, DIF stores the difference to the previous point, DUP counts repeats. A DIF line starts with the last value of the line before, a check that catches damaged files; this reader verifies it on every line.

No. The conversion runs in your browser. The file is not sent anywhere, so proprietary and unpublished spectra are safe to convert here.