Column Width Limiter

WHAT IT DOES

Column Width Limiter is a browser extension that limits the maximum width of text content on a webpage to improve readability. Users can set a custom max-width in pixels or percentage for paragraph elements and text containers (p, div, article, section, main, aside, .content, etc.). The tool applies max-width and margin: auto to center the content, creating a clean, readable column. A toggle enables or disables the width limit, and a reset option restores the default width (720px). Settings are saved per website. The tool is ideal for users who find long lines of text difficult to read and want to create a more comfortable reading experience on websites with full-width text.

WHERE IT RUNS

Column Width Limiter runs on any webpage, overlaying a floating panel that does not interfere with page content. It operates entirely in your browser as a lightweight userscript, injecting CSS to override element widths. It works on any page, whether static or dynamic, with no external dependencies. All settings are stored locally using GM_setValue—no data is ever sent to any server.

HOW TO USE

After installation, open the floating panel by clicking the extension icon. The panel shows the current status (Enabled or Disabled) and a toggle button to enable or disable the width limit. Use the "Max width" input to set a custom width in pixels (100-2000) or select the percentage unit (5-90%). Click the "Set" button to apply the new width. The current width is displayed below the input. Click the "Reset Default" button to restore the default width (720px). Click the "Reapply" button to reapply the width limit if it was removed by page changes. The width and settings are saved per website, so your preferences persist across visits.

REAL MECHANISM — WHY THIS WORKS

Most readability tools rely on modifying the body's style or using a simple max-width on the body element, which may not affect all text containers. Column Width Limiter uses a comprehensive CSS injection approach that applies max-width and margin: auto to a wide range of text-containing elements, including p, div, article, section, main, aside, and common content class names. The tool injects a style element with !important rules to override the page's existing styles. The width can be set in pixels or percentage, allowing for responsive behavior. When set to percentage, the column width scales with the viewport, maintaining the same relative width across different screen sizes. The tool also adds word-wrap and overflow-wrap to ensure text stays within bounds, and sets max-width: 100% on images, videos, and iframes to prevent them from overflowing the column. The width is stored in GM_setValue and automatically reapplied on page load. This approach ensures consistent, reliable, and fully private column width control without requiring any external services or network access.

THE PANEL

The floating panel is fully draggable and remembers its position per site, snapping to the edges of the viewport when dragged near them. You can collapse the panel to a small icon to minimize screen distraction and expand it back with a single click. The panel is resizable from the bottom-right corner, giving you more space to view controls. Press the Escape key to close the panel instantly. The panel remains open across page navigation within the same domain, maintaining your current view state. All preferences—panel position, max-width value, unit, and enabled state—are saved per domain for a seamless experience.

PLEASE NOTE

Column Width Limiter requires the free BotGentz extension to be installed and enabled, as it relies on the cross-extension messaging API provided by BotGentz for DOM access permissions. The tool applies CSS !important rules, which may conflict with page styles that also use !important. The tool applies to a comprehensive list of selectors but may not catch all text containers on all pages. The width limit does not affect text inside fixed-width elements or elements with explicit width constraints. All settings are stored locally in your browser using GM_setValue. No page content, width data, or usage information is ever sent to any server. The extension does not read, store, or transmit any personal information. It only modifies CSS at your request.