BYTETOOLS

Number Sequence Generator

Generate a numeric list from a start, step and count or end value, with zero padding, prefixes, thousands separators and per-line, CSV, JSON or SQL output.

25
Values
1
First
25
Last
24
Range covered

25 values

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

Each value is computed as start + step × index rather than by repeatedly adding the step, so a fractional step like 0.1 does not accumulate floating-point drift down a long list. Values are then rounded to your chosen decimal places and grouped without using the browser locale, which means the numbers look identical on every machine. Everything runs in your browser — nothing is uploaded.

What is the Number Sequence Generator?

This generator produces a run of numbers to whatever shape you need. Choose a start, a step and either how many values you want or the value to stop at, then dress each one with a prefix, a suffix, zero padding and a thousands separator.

  • Count mode or start-to-end mode, with positive or negative steps
  • Zero padding up to 20 digits and 0 to 8 decimal places
  • Prefix and suffix text applied to every value
  • Comma, space, full stop or underscore thousands separators
  • Line, comma, SQL IN, JSON array and CSV output formats
  • Drift-free maths so fractional steps land on exact values

How to use the Number Sequence Generator

  1. 1

    Choose whether to build from a count or from an end value.

  2. 2

    Set the start and the step — a negative step counts down.

  3. 3

    Add zero padding, a prefix such as INV- or a suffix, and a thousands separator if you want one.

  4. 4

    Pick an output format: lines, comma separated, SQL IN list, JSON array or CSV.

  5. 5

    Copy the result, or download it as a TXT, JSON or CSV file.

About the Number Sequence Generator

This generator produces a run of numbers to whatever shape you need. Choose a start, a step and either how many values you want or the value to stop at, then dress each one with a prefix, a suffix, zero padding and a thousands separator. It is the quick fill tool for invoice numbers, ticket IDs, test fixtures and spreadsheet columns.

Values are computed as start plus step times index rather than by adding the step repeatedly, so a fractional step like 0.1 never accumulates floating-point drift down a long list. Numbers are then rounded to your chosen decimal places and grouped without touching the browser locale, which means the output looks identical on every machine you run it on.

Pick the output format that suits where the list is going: one per line, comma separated, a JSON array, a CSV file with a header, or a ready-to-paste SQL IN list with every value properly quoted. It all happens in your browser, with nothing uploaded and nothing stored.

Frequently asked questions

How do I generate a list of numbers with leading zeros?

Set the zero pad field to the total width you want. A pad of 4 turns 7 into 0007 and 123 into 0123. Padding is applied to the digits only, so a negative value keeps its minus sign in front.

Why does my sequence with a 0.1 step come out exact here?

Because each value is calculated as start plus step times its index instead of adding 0.1 over and over. Repeated addition drifts, which is how you end up with 0.30000000000000004. Values are also rounded to your chosen decimal places before display.

Can I create a SQL IN list from a range of numbers?

Yes, pick the SQL IN option in the output format menu. Every value is wrapped in single quotes with any embedded quote doubled, so a prefix or suffix containing an apostrophe cannot break the statement.

How do I generate sequential invoice numbers?

Set the prefix to something like INV-, the start to your next invoice number, the step to 1 and the zero pad to 4 or 5. You will get INV-00042, INV-00043 and so on, ready to paste into a spreadsheet.

What is the maximum length of a generated sequence?

The tool lists up to 20000 values in one run. If your start, step and end span more than that, it generates the first 20000 and tells you, so you can narrow the range or increase the step.

Related tools