Generator Tools
Number Sequence Generator
Generate a number list from a start, end, and step. Output as newlines, comma, JSON, JavaScript, Python, SQL IN, or CSV. Pad, prefix, suffix, decimals.
Quick presets
Drop in one of these and tweak from there, or start from scratch below.
Sequence
Choose how the sequence is sized. Use the start, end, and step to walk a range; or fix the count to spread or step exactly that many values.
Sizing mode
Walk from start to end advancing by step. The count is inferred.
First value in the sequence.
End is inclusive when the step lands on it exactly.
Increment between values. Use a negative number to count backward. Decimals are allowed.
Formatting
Shape every value (decimals, padding, locale) and choose how the list is joined together.
Off by default. When on, every value is rendered with this many digits after the decimal point.
Right-aligns each value to this many characters. Useful for 001, 002, 003 style ID lists.
Inserted before every value.
Inserted after every value.
Disables numeric output in JSON, JavaScript, Python, and SQL modes since "1,000" is not a valid literal in those languages; values are quoted automatically.
Output format
Count
100
Step
1
Min
1
Max
100
Sum
5,050
Nothing is uploaded. The sequence is computed in your browser. Capped at 1,000,000 values per run.
Preview
100 of 100 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, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
Output format guide
- NewlinesDrop a list directly into Notes, Notion, or any plain-text field.
- Comma + spaceReadable inline list for emails, docs, and ticket bodies.
- TabPaste a single column into Excel, Google Sheets, or Numbers.
- JSON arrayAlways valid JSON. Quotes anything that is not a pure number.
- JavaScript / PythonReady to paste into code with your chosen quote style.
- SQL INWrap with WHERE col IN (...). Strings are quoted with single quotes; embedded quotes are escaped.
How to use
- Pick a sizing mode: Start, end, step is the everyday choice; Start, end, count spreads values evenly; Start, count, step takes a fixed number of values from the start.
- Type the start, then either the end and step, the end and count, or the count and step. Use a negative step to count backward; decimals are accepted for both step and bounds.
- Optional formatting: turn on decimal places to fix every value to the same precision, turn on padding to right-align with zeros or spaces, add a prefix or suffix to wrap each value, and toggle locale grouping for 1,000-style thousands separators.
- Pick an output format. Newlines, comma, comma + space, tab, and custom give a plain text list. JSON, JavaScript array, Python list, SQL IN, CSV row, and quoted strings produce a ready-to-paste literal for code or a database client.
- Copy the output with the button next to the box, or read the stats (count, step, min, max, sum) above the result to confirm the sequence matches what you needed.
About this tool
Number Sequence Generator builds an arithmetic sequence of numbers and renders it in whichever format your next step expects. You pick how the sequence is sized: a start, end, and step walks the range until it hits the endpoint; a start, end, and count spreads exactly that many values evenly across the range; a start, count, and step takes that many values from the start advancing by the step. Negative steps count backward, decimal steps accept anything that fits in a double, and a small epsilon absorbs floating-point drift so series like 0.0 to 1.0 by 0.1 reach 1.0 exactly. Every value can be padded with leading zeros (001, 002, 003) or spaces for column alignment, fixed to a number of decimal places, grouped with thousand separators in locale-aware form, and wrapped in a prefix and suffix (ID-001, 5%, item_42). The output box switches between newlines, comma, comma + space, space, tab, semicolon, custom delimiter, JSON array, JavaScript array, Python list, SQL IN body, single-row CSV, and a list of quoted strings. JSON, JavaScript, Python, and SQL outputs detect when a value is still a clean numeric literal and leave it unquoted, but switch to quoted strings the moment a prefix, suffix, zero-pad, or locale-grouped form would otherwise break the syntax of the target language. Stats next to the output show the count, step, min, max, and sum so you can sanity-check a list before you paste it somewhere. Capped at one million values per run to keep the browser responsive. Useful for test data lists, SQL IN clauses, query parameter arrays, mock IDs, lesson examples, label sets, time slot lists, percentage axes, and any other moment you need a clean range of numbers in a specific shape. Everything runs locally; nothing is uploaded.
Free to use. Works in your browser. No signup, no login.
Related tools
You may also like
Random Number Generator
Random integers, decimals, dice rolls, and list picks with unique-only and sort.
Open tool
GeneratorUUID Generator
Generate UUID v4 identifiers in batch.
Open tool
DeveloperMock Data Generator
Build custom rows of fake test data and export to JSON, CSV, SQL, or TS.
Open tool
DeveloperSQL IN Clause Builder
Paste a list of values and get a quoted, escaped SQL WHERE IN clause back.
Open tool
ConverterNumber Formatter
Format numbers with commas, locale grouping, accounting parens, scientific, compact, and custom rules.
Open tool
CalculatorFibonacci Sequence Generator
Generate Fibonacci numbers, look up the Nth term, and watch the ratio approach phi.
Open tool