Character Repeater: Repeat a Character to KB or MB

Why a dedicated character repeater?

Repeating a single character is a different mental task from repeating a phrase. You usually want exact byte counts (1 KB of 'a', 10 KB of '0', etc.) for stress testing, fuzzing inputs, or filling fixed-width fields. This tool optimizes for that — no separator confusion, just N copies joined together.

Common uses

Fixed-width field padding: Generate exactly the right number of spaces, zeros, or asterisks for legacy data formats.
Stress testing input fields: See how a form handles 1,000 'X' characters in a single field.
Visual dividers: Generate a row of ==== or **** for terminal output or documentation.
Sample data files: Create a 1 MB file of 'a' for testing upload limits.
Bytes vs characters: For single-byte ASCII (a–z, 0–9, basic punctuation), character count equals byte count. For multi-byte characters (emojis, accented letters), they differ.

ASCII byte sizes

For a single ASCII character:

Reps	Bytes (UTF-8)	Common name
1,024	1,024 bytes	1 KB
10,240	10,240 bytes	10 KB
102,400	102,400 bytes	100 KB
1,048,576	1,048,576 bytes	1 MB (1024 × 1024)

Common questions

Frequently asked.

The character repeater is meant for short inputs (1 character, sometimes a few). For repeating longer text, use the main text repeater. The 100-char cap and 1,000,000 repeat cap together keep total output under 100 MB even for the worst case.

Functionally identical — this tool uses String.prototype.repeat() under the hood. The advantage is the UI: no need to open DevTools, presets for common byte sizes, and a download button.

Yes. Enter '0' as the character and 1,048,576 as the count. Click Download to save it as a .txt file. This is useful for testing upload size limits or initializing buffer test data.

💬

Repeat a character, byte-precise.