Sometimes you need to import Fixed-Width Text to MongoDB, you can use Withdata FileToMongo as fixedwidth to MongoDB Converter (Importer / Loader).
Works GREAT on Windows, Mac and Linux.
Support Windows, Linux, and macOS.
Support all MongoDB deployment types: standalone, replica set, sharded cluster, and MongoDB Atlas.
Can run in CLI (Command Line Interface), for Scheduled Tasks and Streams, for Automation.
Start Withdata FileToMongo, connect to MongoDB.

Click "1 File To 1 Collection" at task dialog.

Select the "Fixed-Width Text" file type.

1. Open a Fixed-Width Text file.

The source Fixed-Width Text file like this:

2. Choose collection and map columns.

3. Preview and set rows options.

4. Import Fixed-Width Text to MongoDB collection.

After importing, you can view imported data in MongoDB collection.

Click "N File To 1 Collection" at task dialog.

Select the "Fixed-Width Text" file type.

1. Open Fixed-Width Text folder.

2. Set Fixed-Width Text options.

3. Choose collection and map columns.

4. Preview and set rows options.

5. Import Fixed-Width Text to MongoDB collection.

After importing, you can view imported data in MongoDB.

Click "N File To N Collection" at task dialog.

then show the wizard.
Select the "Fixed-Width Text" file type.

1. Open Fixed-Width Text folder.

2. Set Fixed-Width Text options.

3. List collesions, set "Import Type".

4. Map files to collections.

5. Summary.

6. Import Fixed-Width Text data to MongoDB collections.

After importing, you can view imported data.

After importing Fixed-Width Text to MongoDB in GUI, and Saving "Fixed-Width Text to MongoDB" session, then you can:
After importing Fixed-Width Text to MongoDB in Command Line, then you can schedule and automate "Fixed-Width Text to MongoDB" conversion task by:
How long does it take to import Fixed-Width Text to MongoDB?
Is it safe to import Fixed-Width Text to MongoDB using FileToMongo?
Can I import Fixed-Width Text to MongoDB on Linux, Mac OS?
Can I import Fixed-Width Text to MongoDB in command line?
Can I batch import Fixed-Width Text files to MongoDB collections?