Withdata DataFileConverter merges yaml files into one TXT file locally — any number of files, mapped column by column, with the output options of your choice. 100% local, secure, and cross-platform.

Why Choose Withdata DataFileConverter as a YAML Merger?

🔒 100% Local & Secure

All merging runs on your own computer. Nothing is uploaded to any cloud server.

⚡ Fast Streaming Merge

Millions of rows within a minute. Large files are streamed with low memory usage.

📁 Any Number of Files

Add two files or a whole folder, then combine everything into a single TXT file.

🔄 Column Mapping

Files with a different column order or extra columns can be mapped to the output columns before merging.

🖥 Windows, macOS, Linux

Native builds for Windows, macOS and Linux, with a step-by-step GUI wizard and a command line interface.

⏱ CLI & Scheduled Tasks

Save a merge session and run it automatically from Windows Task Scheduler or crontab.

Full Feature Comparison

Feature	Supported details
Input	Any number of YAML files, added one by one or as a folder
Output format	TXT
Merge mode	All input rows into one output file
Running mode	GUI wizard · command line · scheduled tasks
Column handling	Source columns are mapped to the output columns
Output options	Column mapping, encoding, header row
Platform	Windows, macOS, Linux (native, 64-bit)

YAML to TXT — What Changes

Mappings are flattened into delimited text using the keys as the column names. The delimiter is your choice, and nested keys keep their dotted form.

All YAML Merge Options You Need

Merge several YAML files into one TXT file — step by step in the GUI wizard
Merge a whole folder of YAML files in one run
Map the columns of each input file to the output columns
Run the merge from the command line, and schedule it as a scheduled task
All YAML tools and all TXT tools

Same source format, other targets

This page merges YAML into another format. If you need a different output, these pages each do that one job:

All merge tools, by format

Merging into TXT — Notes

Each merged row is written as one mapping in a top-level YAML sequence.
The output indent is 2 spaces by default and can be changed; flow style ({ } / [ ]) can be toggled.
Column names that contain dots (for example address.city) can be written back as nested mappings.
When reading YAML: a top-level sequence of mappings is one row per mapping, nested mappings become dotted column names, and anchors/aliases/tags/multi-document files are not supported.

How to Merge YAML Files (4 Steps)

Open Withdata DataFileConverter and choose Merge (combine multiple files into one).
Add the YAML files you want to merge — two files, a list, or a whole folder.
Check the preview and map the source columns to the output columns; then set the output options (Column mapping, encoding, header row).
Click Convert — the single TXT file is written in seconds. Save the session if you want to run it again from the command line.