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Open and edit large files
that freeze basic editors

Unlike RAM-based editors that load an entire file into memory, UltraEdit uses a disk-based architecture that loads only the portion of a file you need, keeping memory usage stable when working with multi-GB logs, data exports, SQL dumps, and CSV files.

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How UltraEdit opens large files without running out of memory?

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BASIC EDITORS

Most text editors like VS Code or Notepad++
load an entire file into RAM when you open it.
For files over a few hundred MB, that means
slow load times, sluggish scrolling, and in many
cases an out-of-memory error that prevents
the file from opening at all.

Mid
check

ULTRAEDIT

UltraEdit works differently. As a disk-based
editor, it only loads the portions of the file you
are actively working with into memory. The
rest stays on disk. Memory usage remains
stable as you scroll, search, and edit —
regardless of how large the file is.

What types of large files UltraEdit is used for?

The files that most commonly exceed the limits of basic editors:

  • Log files — server logs, application logs, event logs that grow to GB size
  • CSV and TSV files — large data exports from databases or analytics platforms
  • SQL files — database dumps that can run into hundreds of MB or several GB
  • XML files — large configuration files, data exports, and feeds
  • Plain text data files — bulk exports from BI tools, ETL outputs, flat-file databases

How this compares to working with large files in VS Code?

VS Code is a capable editor for code files but was not designed around disk-based large file handling. Opening a file that is several hundred MB or more in VS Code often results in a warning, disabled features, or an unresponsive editor.

UltraEdit does not impose the same limitations because its file handling model is fundamentally different. There is no fixed RAM ceiling for the file — the editor reads from disk and keeps memory usage predictable.

Splitting or searching very large files

When a file is too large to work with as a whole, UltraEdit supports:

  • Find and Replace across multi-GB files — search is performed on disk, not in memory, so even very large files can be searched quickly.
  • Column mode editing — useful for working with structured data in large CSV or fixed-width files without reformatting the entire file.
  • Scripting — UltraEdit’s scripting engine can be used to split large files into smaller chunks, extract specific sections, or automate repetitive edits .

Testimonials

I’ve been using UltraEdit for years to manage large datasets, and its performance is unmatched. The ability to handle huge files without crashing is invaluable.

Felipe S.

Data Engineering Lead
Mid-Market (51-1000 emp.)

I love how it easily handles large text files. I have a db log file that is several GB, and UE quickly opens the file, and I can search the entire document very fast.

 

Kent H.

Vice President, Data Management
Mid-Market (51-1000 emp.)

UltraEdit handles my multi-GB log files effortlessly. The search functionality is incredibly fast and efficient, saving me a lot of time.

Doug F.

Owner and CEO
Small-Business (50 or fewer emp.)

G2 logo

Read more UltraEdit reviews on G2 →

Video Tutorials

Tweaking your settings
for large files

Benchmark: large
file performance

Opening a 35 GB XML
file in UE

Another Video
Example

Optimizing the UltraEdit Text Editor to handle extremely large files.

There are several configuration settings that can be configured to optimize the editing of large files. (Most of them can be found in the Large Files under Advanced → Settings → File Handling → Large Files).

1. Disable Temp Files

Disabling temporary files is probably the most crucial adjustment you can make to improve performance when opening very large files with UltraEdit. As a disk-based editor, UltraEdit only loads small portions of the file into memory, minimizing the impact on your system’s RAM.

Disable Temp Files

2. Disable Line Numbers

Disabling line numbers in UltraEdit can greatly enhance navigation and performance, particularly when working with very large files.
Disable Line Numbers

3. Disable Line Terminator Conversion

Line terminator conversion is a feature that ensures consistent line endings within a file, converting Unix (LF only) or Mac legacy (CR only) terminators to the DOS (CR/LF) format.
Disable Line Terminator Conversion

4. Disable Code Folding

Although Code folding is a useful feature for collapsing and expanding sections of code, making it easier to navigate complex scripts and source files…
Disable Code Folding

5. Disable the Function List

The function list feature in UltraEdit is designed to parse and display all the functions in a file, providing a convenient way to navigate through code.

6. Set a Large File Threshold for the XML Manager

The XML manager in UltraEdit provides powerful tools for viewing and editing XML files. However, it requires parsing the entire file to offer features like tree view, validation, and XPath search. For large XML files, this parsing process can be very slow and consume significant system resources.
Set a Large File Threshold for the XML Manager

7. Disable Syntax Highlighting

Disabling line numbers in UltraEdit can greatly enhance navigation and performance, particularly when working with very large files. Line numbers are typically displayed to help users track their position within the file, but calculating these numbers in real-time for large files can be resource-intensive. Each time you scroll or navigate through the file, UltraEdit needs to calculate and display the line numbers, which can slow down the editor.
Set a Large File Threshold for the XML Manager

8. Disable the Line Change Indicator (LCI)

Disabling line numbers in UltraEdit can greatly enhance navigation and performance, particularly when working with very large files. Line numbers are typically displayed to help users track their position within the file, but calculating these numbers in real-time for large files can be resource-intensive. Each time you scroll or navigate through the file, UltraEdit needs to calculate and display the line numbers, which can slow down the editor.
Set a Large File Threshold for the XML Manager

Download a free trial of UltraEdit. Available for Windows, Mac, and Linux.

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