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Glow automatically wraps markdown content to ensure optimal readability in your terminal.

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The —width Flag

Set a custom text width with the --width (or -w) flag: 
glow README.md --width 100

glow document.md -w 60

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Disabling Word Wrap

Set width to 0 to disable word wrapping: 
glow README.md --width 0
Disabling word wrap may cause text to overflow your terminal width, requiring horizontal scrolling.

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Automatic Terminal Width Detection

When you don’t specify a width, Glow automatically detects your terminal dimensions: 
// Detect terminal width
if !cmd.Flags().Changed("width") {
    if isTerminal && width == 0 {
        w, _, err := term.GetSize(int(os.Stdout.Fd()))
        if err == nil {
            width = uint(w)
        }

        if width > 120 {
            width = 120
        }
    }
    if width == 0 {
        width = 80
    }
}
The detection logic (main.go:193-207):
  1. Terminal Detection: Checks if stdout is a terminal
  2. Width Retrieval: Gets the actual terminal width
  3. Maximum Cap: Limits width to 120 columns for readability
  4. Fallback: Defaults to 80 columns if detection fails

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Default Width Behavior

1

Terminal Width Detected

If running in a terminal, Glow reads the actual terminal width
2

Apply Maximum (120 columns)

If terminal width exceeds 120 columns, it’s capped at 120 for optimal readability
3

Fallback (80 columns)

If width cannot be detected or is 0, defaults to 80 columns

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Why Cap at 120 Columns?

Wide terminals can make text harder to read. Research shows optimal line length for readability is 60-100 characters. The 120-column cap ensures:
  • Comfortable reading experience
  • Prevents excessive eye movement
  • Maintains text structure

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Width in Glamour Rendering

The width is passed to Glamour’s rendering engine: 
// initialize glamour
r, err := glamour.NewTermRenderer(
    glamour.WithColorProfile(lipgloss.ColorProfile()),
    utils.GlamourStyle(style, isCode),
    glamour.WithWordWrap(int(width)),
    glamour.WithBaseURL(baseURL),
    glamour.WithPreservedNewLines(),
)
This controls how markdown elements wrap:
  • Paragraphs
  • Code blocks
  • Lists
  • Tables
  • Block quotes

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Width with Different Output Modes

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Standard Output

# Renders at detected terminal width (max 120)
glow README.md

# Custom width
glow README.md --width 80

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Pager Mode

Width is applied before piping to the pager: 
# Content wrapped at 100 columns, then paged
glow README.md --width 100 --pager

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File Redirection

When redirecting output, specify width explicitly: 
# Use default 80 columns for redirected output
glow README.md > output.txt

# Specify custom width
glow README.md --width 100 > output.txt

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Configuration File

Set a default width in your configuration file (~/.config/glow/glow.yml): 
width: 100
The --width flag overrides the configuration file setting.

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Examples

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Narrow Width for Side-by-Side Viewing

# Good for split terminal panes
glow README.md --width 60

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Wide Width for Detailed Content

# Use full 120 columns for technical docs
glow documentation.md --width 120

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Responsive to Terminal Resize

# Automatically adjusts to current terminal size (up to 120)
glow README.md

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No Wrapping for Code-Heavy Content

# Disable wrapping for files with wide code blocks
glow code-examples.md --width 0

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Width and Paging Interaction

The width setting affects how content is formatted before it reaches the pager: 
# Content wrapped at 80 columns, then sent to less
export PAGER="less -r"
glow README.md --width 80 --pager

# Width auto-detected, content rendered directly
glow README.md --width 100
For the most comfortable reading experience, let Glow auto-detect your terminal width. It will intelligently cap at 120 columns even on ultra-wide displays.

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