When you are working with a large HTML file, knowing that a class name or attribute exists somewhere is not enough — you need to find exactly where it appears, how many times, and in what context. HTML Viewer Pro includes Find in code, a search tool that works across your HTML, CSS, and JavaScript with case-sensitive, whole-word, and regular expression options — all running locally in your browser.
What "search HTML code online" should actually do
A basic text search finds matches, but real code navigation requires more:
- Find next / previous — cycle through multiple matches without losing your place or re-running the search
- Case-sensitive search — distinguish
Buttonfrombuttonwhen working with component names and CSS classes - Whole-word matching — avoid matching
hero-titlewhen you are searching fortitle - Regular expressions — search for patterns like
data-*attributes, repeated class prefixes, or any variable content - Replace (when needed) — rename a class, update an attribute value, or swap out a URL across the entire file
How to search HTML in HTML Viewer Pro
- Open HTML Viewer Pro and load your HTML.
- Click Find in code in the toolbar, or press Ctrl+F / Cmd+F.
- Type your search term — for example, a class name like
hero-titleor a tag like<section. - Use the next / previous arrows to move between matches. The editor scrolls to each match and highlights it.
- Toggle Case, Word, or Regex in the search bar to refine results.
- Use the Replace field to update matched values across the file.
Search CSS online in panels mode
In HTML / CSS / JS panels mode , each panel has its own Find in code search. To search CSS:
- Switch to HTML / CSS / JS panels from the toolbar.
- Click the Find icon in the CSS pane header (or focus the CSS pane and press Ctrl+F / Cmd+F).
- Search for selectors, properties, or values — for example,
flex,.card, or a color token like#1a1a1a.
This is particularly useful when you want to find all uses of a specific color, locate a selector that affects a particular element, or check whether a property is defined before overriding it.
Search JavaScript in the same workspace
JavaScript searches work the same way in the JS pane. Common use cases:
- Find all calls to a function — search for the function name to see everywhere it is invoked
- Locate a
console.logbefore exporting to production - Search for an event listener by type — search
addEventListenerto see every event binding - Find variable usages with whole-word matching to avoid false positives from partial matches
Find vs inspect vs validate
These three tools solve different but complementary navigation problems in HTML Viewer Pro:
- Find in code — you know what text or pattern you are looking for, and you want to locate it in the source. Fast, direct, works across HTML/CSS/JS.
- Inspect element — you can see something in the preview and want to find its source line. Click the visual element, jump to the code.
- Validate — you want to know what is structurally wrong, not find a specific term. Validation surfaces unclosed tags, bad nesting, and duplicate IDs.
Using them together is faster than using any one alone. A common workflow: validate to find the category of problem, inspect to locate the specific element visually, find to confirm whether the pattern appears elsewhere in the file.
Regular expression search examples
Regex search in Find in code makes complex pattern matching practical without leaving the editor:
data-[a-z-]+— find all custom data attributesclass="[^"]*btn[^"]*"— find all elements with a class containing "btn"https?://[^\s">]+— find all URLs in the markup<img[^>]*alt=""— find images with empty alt attributes (accessibility check)style="[^"]*color[^"]*"— find inline color styles
Regex patterns use JavaScript syntax. The search is applied to the full text of the active panel.
Privacy: search without uploading
Find in code runs entirely in your browser. Your HTML, CSS, and JavaScript source are never sent to a server — not for the search, not for the replace, not for any other operation. This makes it safe to use with confidential HTML — client code, internal templates, or anything else you would not paste into a public tool.