How do Start and Length work?

Start uses a zero-based byte position. Length sets the removal size. For ABCDEFGH, Start 0 and Length 5 leave FGH. Negative Start values count from the end.

What input does Bytes Remover accept?

Paste text into Input. This page does not provide a file picker or decode hexadecimal input. Latin1 text uses one byte per code unit. If any character exceeds 255, the entire input uses UTF-8.

Do positions count characters or bytes?

Positions count bytes. A UTF-8 character can occupy several bytes. Removing part of that sequence can produce invalid text.

What does Bytes Remover return?

Select Run tool, then Download. The drop-bytes.bin file contains the remaining bytes. Apply to each line repeats the removal on each line.

Bytes Remover | Tool Factory

Tool workspace

Your input stays in this browser.

Needs input

Run the tool when your input is ready.

Input

Options

Start

Length

Apply to each line

Your result appears here

Remove a byte range from pasted text, or the same range from every line, in your browser. Downloads the remaining bytes as a .bin file.

This tool runs open-source code from CyberChef by GCHQ (Apache License 2.0). See open-source credits.

Bytes Remover deletes a run of bytes from pasted text and returns the rest as a download named drop-bytes.bin. Start is a zero-based byte offset; a negative Start counts back from the end. Length is the number of bytes to delete. With Apply to each line on, the same cut repeats on every line.

The result is a binary download named drop-bytes.bin, not text on the page. It holds every byte outside the removed range.

Strip a fixed-width timestamp or line number from every line of a log.
Remove a known-length label, such as a 4-byte prefix, from pasted text.
Trim a fixed number of trailing bytes with a negative Start.

Instructions

Paste the text into Input. Count positions in bytes from 0.
Set Start and Length. For ABCDEFGH, Start 0 and Length 5 leave FGH.
To cut from the end, use a negative Start. Start -3 with Length 3 leaves ABCDE.
Turn on Apply to each line to strip a fixed-width prefix, such as a 17-byte timestamp, from every line.
Select Run tool, then Download. Open drop-bytes.bin in a text editor to check the result.

Example

Input: ID: 17 ID: 42

Settings: Start 0, Length 4, Apply to each line on

Result: A 5-byte drop-bytes.bin file that contains 17, a line feed, and 42

With Apply to each line off, the tool removes only the first 4 bytes of the whole input.

Limits

There is no file picker and no hex input. You cannot load a binary file here.
Characters up to U+00FF become one byte each. If any character is above U+00FF, the whole input is encoded as UTF-8. Positions then count UTF-8 bytes, and € takes 3.
A cut inside a multi-byte character leaves invalid UTF-8. Removing 1 byte from €A leaves the bytes 82 AC 41.
A Length past the end removes everything after Start without an error. Start 1 and Length 10 on ABC leave A.
A negative Length removes bytes before Start. Start 2 and Length -1 on ABCDEFGH remove B.