Free SEO Tools Online
Going into 2026 these are the 7 free SEO tools I still open most weeks: diagnostics, keyword analysis, text converters and list utilities, for the small jobs that come up mid-task and never justify a paid seat. No signup, no email, no trial. Six of the seven never send your text anywhere — the domain rating checker is the one exception, because it has to ask Ahrefs.
Domain Rating Checker
Check any site's Ahrefs Domain Rating, one domain or twenty at once. Real DR from the official Ahrefs API rather than an estimate.
Google Penalty Checker
Pick the month your traffic fell and see every confirmed Google algorithm update from that window, what it targeted and how long it rolled out.
Keyword Density Checker
Rank every term in your text by frequency and density, or check one word or multi-word phrase against the correct phrase-density formula.
Word Counter
Words, characters with and without spaces, sentences, paragraphs, reading time and speaking time, all counted as you type.
Case Converter
Change text between lowercase, UPPERCASE, Sentence case, Title Case, alternating and inverse case, then copy or download it.
Spintax Generator
Turn a synonym list into {word1|word2|word3} spintax, build it word by word, or expand existing spintax to preview the variations.
Column to Comma Converter
Join a spreadsheet column into a comma-separated list, or split a comma-separated list back into a column. Custom separators and quote wrapping.
Looking for a bigger tool?
These seven are mine, and free. For the commercial SEO software, verified pricing, real limitations and which ones I have used myself, browse the SEO tools directory. Or if you need a utility that does not exist yet, tell me.