I'm looking for a text file viewer (ideally an editor too) that will do the following (ordered from most to least important):

  1. Load the file quickly (10 seconds for a 10 GB file off an SSD)
  2. Once the file is open, jump to specific line numbers fairly quickly (~1 second per lookup)
  3. Have decent text search/replace mechanisms, ideally with regex support.
  4. Ideally, avoid dumping the entire file into RAM because I quickly run out (I've got 32GB but still).

I've tried TextPad and UltraEdit so far. I've been using the former for years with much success, but the line number calculation seems to break when opening files larger than 10 GB. UltraEdit looks fine, but is very expensive (close to $100 per year). I'm wondering if there is a better/cheaper alternative.

  • 2
    Tried notepad++? Jan 4, 2016 at 5:31
  • 3
  • If it is to avoid loading the entire file into RAM the maximum jump time could be longer than, or equal to, the load time not the other way around. Jan 4, 2016 at 7:12
  • @SteveBarnes Not necessarily. One could scan the file at load time, save the offset of each end of line and you're done. No need to leave the actual file contents in memory.
    – Gili
    Jan 4, 2016 at 7:30
  • Yes but as soon as you edited it, it would have to read the lot. Jan 4, 2016 at 8:57

3 Answers 3


I wrote a program which outputs very large files, about 6 GB and above. I view them with glogg.

glogg is fast, supports grep/egrep-like regular expressions and loads file directly from disk without putting it into RAM.

Website: http://glogg.bonnefon.org/

  • Glogg has been the best log viewer i've known Oct 18, 2016 at 10:12
  • Unfortunately glogg seems unmaintained nowadays. There is and active fork github.com/variar/klogg
    – fav
    Aug 24, 2021 at 19:43

I would recommend SlickEdit. It meets your requirements of,

  • Loads files very quickly
  • Available on multiple platforms including Windows
  • Supports Editing
    • Automatically reformat code when typing, pasting, or performing syntax/alias expansion.
    • Syntax expansion automatically expands common block structures (e.g. if, for, try) after typing keyword.
    • Auto-Complete reduces keystrokes by completing symbols as you type.
    • SmartPaste® automatically reindents pasted lines of text.
    • Choose from 15 keystroke emulations including Brief, CodeWright, Vim, and Emacs.
    • Multiple cursors and selections.
    • Create custom typing shortcuts with Aliases.
    • Dynamic Surround - Surround existing lines of code with block statements or tags.
    • Create reusable modules/units of code with Code Templates.
    • Backup History maintains a version history for a file each time you save.
    • Edit files up to 2 TB in size.


Designed by developers for developers, SlickEdit’s award-winning source code and text editor is respected for its rich set of coding tools and powerful time-saving programming features. A true cross-platform, multi-language editor, SlickEdit gives programmers the ability to code in over 40 languages on 9 platforms.

Slick Edit UI

  • 2
    FYI: Standard Edition for 1 OS and 1 named user is 150$, Professional Edition 300$. Jan 6, 2016 at 22:30
  • @ThomasWeller True, but it comes with A LOT of features and it's not a subscription
    – Tom
    Jan 6, 2016 at 22:34

I would also like to add Log Expert. It can view very large files (but cannot edit them). It's very lightweight (only a few megabytes) and is available for Windows being completely open source.

Log Expert

  • You are a developer needing a nice tail application for MS Windows?
  • You are in the need for a powerful logfile analysis tool?
  • You love logfiles?
  • You live in your logfiles?
  • Or at least: you have to work with them?
  • Download LogExpert if you answered "yes" to any of the questions above!

Log Expert UI

  • Explaining downvotes help improve answers...
    – Tom
    Sep 15, 2016 at 15:56
  • 1
    LogExpert is useless for files that contain more than 10000 log records; it starts to "eat" all CPU time on single CPU core even when tail functionality is disables. Not for big log files for sure. Not for real time updates (hangs quickly on large files).
    – Vitalii
    Jun 19, 2019 at 15:11

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