Some black hat tactics are specific enough, and persistent enough, that they're worth understanding individually rather than just filed under "black hat SEO" in the abstract. Cloaking, hidden text, and doorway pages are three of the oldest tricks in the book — and despite being decades old, variations of all three still show up today, still get caught, and still carry real consequences.
Cloaking
Cloaking means showing search engines different content than what a human visitor actually sees — optimized, keyword-rich content for the crawler, and a completely different page for everyone else. It's one of the most clearly-defined violations in every major search engine's guidelines, because there's no legitimate reason to show a crawler something a visitor never sees. Detection has gotten very good at comparing what's served to different user agents, and getting caught typically results in a severe manual penalty.
Hidden Text
Hidden text is content that's technically on the page but invisible to visitors — white text on a white background, text shrunk to an unreadable size, or content positioned off-screen. The intent is to stuff keywords into a page without disrupting its visual design. Search engines render pages visually now, much closer to how a browser does, which makes this particularly easy to catch: if it's invisible to a person, it's very likely visible to whatever is checking.
Doorway Pages
Doorway pages are pages created purely to rank for a specific search term and funnel visitors elsewhere — often many near-duplicate pages, each targeting a slightly different keyword variation, all leading to the same destination. They provide little to no unique value on their own, existing purely as an entry point. Search engines have specifically targeted this pattern, since it directly works against showing genuinely relevant, unique results.
Why These Still Show Up
Despite being well-understood violations, all three persist because they're relatively easy to implement with the wrong tools or advice, and someone unfamiliar with current guidelines can stumble into a version of them without realizing it — an old plugin quietly hiding text for "SEO," or a template auto-generating near-duplicate location pages that function as doorway pages by accident.
> Tip: If a website builder, plugin, or agency is doing something to a site that you can't see or fully explain, that's worth investigating specifically — accidental cloaking or hidden text is more common than the deliberate kind, especially on sites managed by outside vendors.
A Simple Framework for Staying Clean
- Confirm what search engines see matches what visitors see — check the rendered source directly
- Audit for any text with suspiciously small size, matching background color, or off-screen positioning
- Review any set of near-identical pages for genuinely unique value, not just a swapped keyword or city name
- Ask any outside vendor directly whether their tactics could be considered cloaking, hidden text, or doorway pages, in plain terms
Comparing a page's rendered content against its actual source code, and checking how it appears in a Google cache checker, is a fast way to confirm there's no mismatch between what's being served and what's actually visible.
These three tactics are old enough to be considered SEO history, and detection for all of them is more mature than ever — anything relying on a mismatch between what's shown and what's hidden is operating on borrowed time, deliberately or not.