Fixed Width to CSV
Convert fixed-width data into CSV.
Columns defined by position
Fixed-width data uses column positions rather than separators — each field occupies a set number of characters — a format common in older systems and mainframe exports. This converts fixed-width data into CSV, in your browser.
Load your fixed-width data and define the column widths.
Parsing a positional format
Fixed-width format is a relic that is still very much alive, especially in data from legacy systems, banking, government and mainframes, where fields are aligned in fixed positions rather than separated by a delimiter. Its quirk is that the structure is entirely positional — a field is defined by which character columns it occupies, so parsing it correctly requires knowing exactly where each field starts and ends, unlike a delimited format that marks boundaries with a separator. Getting the column widths right is the whole task; a slight misalignment shifts everything. Converting to CSV turns this rigid positional data into the flexible, widely-supported delimited format that modern tools expect, making legacy data usable in current systems. This is a genuine need for anyone integrating with older systems that still export fixed-width files. Doing it in the browser keeps potentially sensitive records — financial or governmental data often comes in this format — local and private on your own device.
Common questions
What is fixed-width data?
A format where each field occupies a set number of character positions rather than being separated by a delimiter — common in legacy and mainframe systems.
What is the key to parsing it?
Knowing exactly which character columns each field occupies, since the structure is entirely positional — a slight misalignment shifts everything.
Is my data uploaded?
No. The conversion happens in your browser, so the data stays on your device.