merge-json-files.com

Free Online TXT File Splitter Tool

This tool splits one large text file into multiple smaller ones. You can split by line count, file size, or by a custom delimiter. Runs in your browser, free.

TXT File Splitter

Want to test with real files?

Download Sample TXT Files
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TXT File Splitter Before & After

TXT split result preview

Input: One Large TXT File
text
line 0001: app started
line 0002: loading modules
line 0003: fetching configs
...
line 4200: completed
Output: Chunked Files
text
events_part_1.txt (lines 1-1000)
events_part_2.txt (lines 1001-2000)
events_part_3.txt (lines 2001-3000)
events_part_4.txt (lines 3001-4000)
events_part_5.txt (lines 4001-4200)

How the TXT File Splitter Works

Four simple steps

1

Upload TXT File

Drop your .txt or plain text file directly into the splitter.

2

Pick Split Method

Split by lines, target chunk count, or max chunk size.

3

Configure Output

Optionally trim lines or remove empty lines before splitting.

4

Download Chunks

Preview each chunk and download clean .txt parts instantly.

TXT File Splitter Use Cases

When to use a text splitter

API Size Limits

Split oversized text payloads into smaller files that pass upload and import limits.

Batch Processing

Feed chunked text files to ETL jobs and workers for faster pipeline throughput.

Editor Performance

Break giant logs into smaller files that open smoothly in VS Code or Notepad++.

Team Review

Distribute chunks among teammates to review transcripts or logs in parallel.

TXT File Splitter FAQ

Common questions

TXT File Splitter Scripts

Python & Bash

Pythonsplit_txt.py
from pathlib import Path

def split_file(path, lines_per_chunk=1000):
    lines = Path(path).read_text(encoding="utf-8").splitlines()
    base = Path(path).stem

    for i in range(0, len(lines), lines_per_chunk):
        chunk = lines[i:i + lines_per_chunk]
        out = Path(f"{base}_part_{i // lines_per_chunk + 1}.txt")
        out.write_text("\n".join(chunk), encoding="utf-8")

split_file("large.txt", lines_per_chunk=1000)
Bashterminal
# Split into 2000-line chunks
split -l 2000 events.txt events_part_

# Rename with .txt extension
for f in events_part_*; do mv "$f" "$f.txt"; done

TXT File Splitter Complete Guide

In-depth walkthrough

Split by lines vs split by size vs split by delimiter - which to pick

Split by line count: use this when each line is a record (log files, CSV rows, JSONL). You get equal chunks with predictable record counts. Example: split a 100,000-line log file into 10 files of 10,000 lines each.

Split by size: use this when you have a file size limit (email attachments, upload restrictions). The tool splits at the target size, which may split mid-line. Example: split a 50MB text export into 10MB chunks to fit within an API upload limit.

Split by delimiter: use this when your file has natural section breaks (--- in markdown, === in reports, custom separators in exports). Each chunk is a meaningful unit. Example: split a markdown document by ## headings so each chapter becomes a separate file.

Most users need split by line count because it preserves record boundaries and creates predictable chunks. Use split by size only when file size is the constraint, not record count. Use split by delimiter when your file has logical sections marked by a separator.

If you are not sure which to use, start with split by line count. It works for most text files and keeps each line intact, making the output easier to process.

Common use cases

Log file rotation: splitting a large server log into daily or weekly chunks for archiving. If your application writes to a single log file that grows to 500MB, split it into 50MB chunks and archive them by date. This makes searching logs faster and keeps your log directory manageable.

Batch processing: splitting a 1 million row dataset into 10k-row chunks for parallel processing. If you have a script that processes text line-by-line, split the input into 100 files of 10,000 lines each and run 10 workers in parallel. This reduces processing time from hours to minutes.

Email or upload limits: splitting a large text export to fit within attachment or upload size limits. Many email providers limit attachments to 25MB. If your export is 100MB, split it into 4 files of 25MB each and send them separately or upload them to a service with size restrictions.

Markdown docs: splitting a long document into chapters by using headings as delimiters. If you have a 200-page markdown book with ## Chapter headings, split by ## to create one file per chapter. This makes editing and version control easier.

Doing this in the terminal instead

For Linux or Mac, use split -l 1000 file.txt chunk_ to split by line count. This creates chunk_aa, chunk_ab, chunk_ac, etc. Add mv chunk_* chunk_.txt to add .txt extensions. For size-based splitting, use split -b 10M file.txt chunk_.

For Windows PowerShell, use Get-Content file.txt -ReadCount 1000 | ForEach-Object {$_ | Out-File "chunk_$i.txt"; $i++}. This reads 1000 lines at a time and writes them to separate files. PowerShell is slower than the Linux split command but works on Windows without installing extra tools.

Terminal methods are better for automation and recurring splits. If you need to split files on a schedule or as part of a script, use the command line. For one-off splits or when you need a preview before downloading, use the browser tool above.