Left-pad a List
Left-pad a list with one or more items. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use Left-pad a List
- 1. Paste your list. Enter your items into the input pane, one per line. Any list you need extended with filler items at the beginning works here.
- 2. Enter a pad item. Type the value to insert before your list in Pad item, such as a placeholder word, a zero, or any repeated filler value.
- 3. Set the number of copies. Enter how many times the pad item should be inserted in Copies. That many copies of the pad item are placed before your original list.
- 4. Copy the padded list. The output pane shows the pad item repeated at the front, followed by your original items. Copy the padded result wherever it is needed.
When to use Left-pad a List
Left-pad a List inserts one or more copies of a filler item at the start of a list. Use Left-pad a List whenever a list needs extra leading placeholder entries before the real data begins.
- Adding blank leading rows to a spreadsheet import. A spreadsheet import expects a couple of header or spacer rows before the real data starts, and left-padding your list with a blank placeholder inserts them.
- Simulating missing early data points in a chart. A chart series is shorter than others and needs leading placeholder values to align its start with a longer series, which left-padding provides.
- Reserving leading slots in a fixed-position list. A layout reserves the first few slots for something added later, and left-padding the current list with a placeholder keeps the real items starting at the correct position.
- Prepending a repeated warning label. A list needs the same warning line repeated several times at the top for visibility, which setting the pad item to that warning text and choosing several copies produces directly.
Examples
Prepend two pad items
Input
one two
Output
x x one two
About the Left-pad a List tool
Left-pad a List is a free online tool that works entirely inside your web browser. Left-pad a list with one or more items. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 114 List utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
You can shape the output with 2 settings, including Pad item and Copies, and the result refreshes the moment you change one. A worked example further down the page shows exactly what the tool produces for a real input.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Is Left-pad a List free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.