Number sequence generator
Generate a list of numbers from a start to an end value with any step.
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Number sequence generator
Set a start, an end and a step, and this generator writes out the whole run of numbers for you. It is the quickest way to produce test data, invoice or order numbers, SKU lists, sequential file names, ID ranges for a bulk import, or the numbered options in a survey — anything where you would otherwise drag a spreadsheet cell down a thousand rows.
Arithmetic mode adds the step to each term: 0, 5, 10, 15. Geometric mode multiplies instead, so a ratio of 2 gives 1, 2, 4, 8, 16, and a ratio of 0.5 halves every term — handy for powers of two, cache sizes or doubling schedules. Decimal steps work as well, and each term is rounded back to the precision you asked for, so a step of 0.1 prints 0.3 rather than 0.30000000000000004. If the start is higher than the end, the sequence simply counts down; the sign of the step is oriented for you.
Zero-padding lines the numbers up at a fixed width — 001, 002, 010 — which keeps file names sorting correctly in any file manager. A prefix and a suffix wrap every number, turning a plain range into IMG_009.jpg or a set of item-1.txt names. You can repeat each number several times in a row when you need grouped rows, and choose whether the output arrives one per line or separated by commas.
Everything is generated in your browser in plain JavaScript, so nothing is sent to a server and the numbers stay on your device. The tally under the output shows how many numbers you got, the first and last term and the character count. Very long runs are capped at 200,000 numbers and 10 MB of output so the tab never freezes.