Keyword Highlighter

Monitor pages and highlight saved keywords without changing the page DOM.

■ Works on pages where other highlighters break Most highlighting extensions insert <span> elements into the page. That is why they lose their highlights when a single-page app re-renders, why they ask you to reload, why they slow down once there are many matches, and why they sometimes break the layout. This one never rewrites the page. It draws with the CSS Custom Highlight API, so it cannot collide with the site's own JavaScript or CSS. It reaches into Web Components (YouTube, for one) and embedded iframes. ■ Register "cafe" and "café" lights up too Matching folds full-width and half-width characters, hiragana and katakana, letter case, and accents. No configuration — it works from the first keyword. ■ Compare dates and numbers as values Narrow by value: deadlines on or after the 15th, amounts of 1,000 or more. When you add a keyword, choose "Date" or "Number" as the kind. The comparisons are = < > <= >=. A date keyword uses one format, chosen from seven — 09/15/2026, 15 Sep 2026 and 2026-09-15 among them — and matches only dates written that way. The same day in another format does not match: nothing but the format decides how a date reads. Add one keyword per format to follow more than one. A number keyword has no format to choose. It reads thousands separators, decimals and negatives. It does not read units or currency symbols, so "100 million" is compared as 100 — and since years and page numbers are numbers too, a bare number keyword matches a lot. Narrow it down with the sites you monitor and with excluded phrases. ■ Decide without reading the page The side panel lists every match with the text around it. Read only what surrounds "termination" in a long agreement, or "remote" in a long job posting, instead of scrolling to look for them. Per-keyword counts are shown too, so when the page is drowning in colour you can see which keyword is responsible. ■ Everything happens in the side panel Clicking the toolbar icon opens the side panel. No settings tab ever opens. Add keywords, change colours and limit lists to certain sites while you are still looking at the page. ■ Eight presets to start from Shopping & subscriptions / Travel bookings / Rental agreements / Investment risk / Scam warning signs / Job hunting / Contract review / Before screen sharing A starting point when you do not yet know what to register. One click copies a preset into your own lists, and from then on it is yours to edit. ■ Help that shows its working The side panel explains the five match modes and the folding it does for you, with worked examples of what matches — and of what deliberately does not, and why. ■ When menus and footers light up too much Category names in the global navigation, the sitemap in the footer, the "related articles" beside a story. You are looking for one match in the article and half a dozen light up around it first. Turn on "Do not highlight in navigation, headers, footers or sidebars" in the list's settings, and anything found around the edges of the page stops being a match for that list. Clicking a highlight offers the same setting without leaving the page. What you leave out appears in neither the count nor the list. That is not the same as a match inside a collapsed section: those are only out of sight, so they still count. What gets left out is decided by the HTML a site is built from. A column that looks like a sidebar is left alone unless the site marks it up as one — guessing where the edges are would sometimes hide the article you came to read. ■ Take the page you just read with you Right-click and choose "Copy this page" to put the page's text on the clipboard, with the title and URL at the top so you know where it came from. Headings, lists and tables keep their shape; what is not on the screen — link targets and the like — stays out. On pages that are not laid out as an article there is no article to find, so the whole page is copied and you are told that is what happened. Some sites block the right-click menu. Hold Shift while right-clicking. ■ What it can't do (stated up front) · It does not highlight inside text inputs · It does not highlight inside PDFs · Styling is limited to text colour, background colour and an underline — no borders, no bold (the price of not rewriting the page) · No morphological analysis for Japanese ■ Free No ads. No paid tier. No analytics. Your keywords and the pages you visit never leave your device, and the extension never contacts a server. ■ What changed in 1.0.4 · Each list can skip navigation, headers, footers and sidebars (above) · Clicking a highlight offers that setting without leaving the page · Each keyword can carry an underline, straight or wavy · Keywords can be reordered: move to top, up, down · Fixed the keyword filter clearing itself the moment you opened a keyword · Help covers all of the above ■ What changed in 1.0.3 · Keywords that compare dates and numbers as values (above) · The keyword box now asks what kind of keyword you are adding · Date formats are ordered to match your browser's language · Comparison symbols are now = < > <= >= · Help now covers date and number keywords ■ What changed in 1.0.2 · Fixed a bug where some pages reported more matches than they actually had · Fixed matches that stayed marked as hidden after scrolling or unfolding revealed them. The count now also shows how it splits between visible and hidden · Renamed the "allow spelling variants" setting to "typo tolerance", because the name did not describe what it did. Spelling variants — full-width and half-width, hiragana and katakana, upper and lower case — are folded for you at all times, with or without that setting · Added help covering the three match modes, inflection and typo tolerance, and the folding, with worked examples of what matches and what does not · The version you are running is now shown · You can copy the text of a page you are reading to the clipboard (above) ■ About permissions Installing asks for nothing broad. The first time you open the side panel, you choose "all sites" or "only these sites", so you decide once you can see what the permission is for.