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Character repeater

Repeat a character, byte-precise.

Repeat a single character up to 1,000,000 times. Generate exact byte counts (1 KB, 10 KB, 1 MB) for fixed-width padding and stress testing.

The character repeater repeats a single character up to 1,000,000 times to build exact-length strings for padding and stress testing.

Character repeater

0 chars 0 words 0 lines
Single character or short string. Max 100 chars input.
"1 KB" gives you exactly 1,024 of the character (one kilobyte if your char is single-byte ASCII).
Output 0 × repeats
0 chars 0 lines

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:

RepsBytes (UTF-8)Common name
1,0241,024 bytes1 KB
10,24010,240 bytes10 KB
102,400102,400 bytes100 KB
1,048,5761,048,576 bytes1 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.

Related

Other repeater tools.

💬

WhatsApp repeater

Repeat WhatsApp messages with one-tap send.
🎉

Emoji repeater

Build emoji walls for chats and posts.
🔁

Word repeater

Single-word repetition, optimized.
📋

Line repeater

Repeat each line of multi-line input.
⚡

Stress test generator

Generate 1 KB to 10 MB of test data.
📄

Lorem Ipsum

Paragraphs for design mockups.

Sources & standards

The technical claims on this page are based on primary specifications and vendor documentation. Last verified 13 July 2026.

Byte-precise strings for testing

The character repeater is the tool to reach for when you need an exact-length string. Repeat a single character up to 1,000,000 times to produce fixed-width padding, fill a field to its maximum, or create a known input for a parser. The live character counter updates as you go, and the presets jump straight to common byte sizes so you do not have to do the math.

Common uses

Developers and QA engineers use it to test database column limits (for example VARCHAR(255) or a 65,535-character TEXT field), to check how forms handle overflow, to pad values to a fixed width, and to generate simple buffers of a single byte value. Paste the result into a form, or download it as a .txt file to upload.

Character repeater vs. stress test generator

Both make large outputs, but they measure differently. The character repeater counts repetitions of one character; the stress test generator targets an exact byte size (1 KB to 10 MB) and pads the final piece to hit it precisely. Use this tool when the character and count matter; use the stress test generator when total bytes matter. See the testing guide for worked examples.