From MozillaZine Knowledge Base
Some options available for comparison of web page text and source.
Side by side alignments
- "Fox Splitter (formerly Split Browser)" extension. Splits the content area of the browser tab/window as you like, top, right, bottom, left and split windows can be additionally split. Close All Split Browser" closes all of them at once. Split browsers can be closed by their closebox. You can tile all of tabs as split browsers, and, gather split browsers to tabs
- "Split Tab" extension, view two pages in same tab from "Split Tab" on contextmenu. Normal click opens side by side, other click (right click) opens stacked (top/bottom). Prompts for urls before opening (preselected urls are current page and google).
- You used to be able to open a webpage in a sidebar (target="_search") and used to be able to open a bookmark in the sidebar in Firefox, which were nice for a cheatsheet on the left. (Bug 438526) (Bug 215175) Need replacements of these features.
Above and below alignments
For a comparison view of About:config_entries table and actual about:config settings, use "Fox Splitter (formerly Split Browser)" extension with one above the other so entire table rows can be visually compared.
- Windows-7 keyboard shortcuts: WinKey+ArrowKey Left/right/Max/Min/Normal. Use "WinKey + ←" to align one window on left, half of screen, and "WinKey + →" to align another window on the right half of screen. The left and right arrow options also work across two screens, first on one screen then extending to the other screen. Double-clicking on the title bar switches between full screen and restored.
- "PageDiff", Firefox extension to compare page source, helps web developers and designers to see HTML-code(text) differences between web pages.
- Use Google Docs To Compare Two Text Files online (HTML, Word, .txt).
- "Quick Diff Online Tool" to compare text by pasting in before/after text areas of a webpage.