PrepostSEO

PrepostSEO is a suite of more than 150 free browser-based utilities aimed at webmasters, students and SEO practitioners: plagiarism checking, paraphrasing, grammar checking, domain authority lookup, keyword density analysis, backlink checking, image compression and dozens of smaller conversions and calculators. Most work without an account, which makes it a practical bookmark for one-off tasks rather than a platform you commit to. Judge it by that role. Free tool suites are funded by advertising and usage caps rather than subscriptions, so expect ads, daily limits on the heavier tools and accuracy well below dedicated paid alternatives, particularly on plagiarism and AI detection where false results in both directions are common. Useful for quick checks and for people who cannot justify a paid stack; not a substitute for one where the answer actually matters.