Free Keyword Stemmer & Variant Generator — Expand Seed Keywords
One seed keyword can hide dozens of search variations. Enter your seeds and this tool generates plurals, verb forms, comparatives, agent nouns, and adverbs using clear, documented suffix rules — then groups everything per seed with copy and CSV download. All in your browser.
Keyword Stemmer & Variant Generator
Expand seed keywords into plurals, verb forms, comparatives & more — rules fully documented.
1 Enter seed keywords
2 Variant groups
3 Generate variants
🌱 Variants generated
How it works
The tool stems the last word of each seed (so “compress pdf” stems “pdf”, “budget planner” stems “planner”) and applies these documented rules:
- Plurals: +s normally · +es after s, x, z, ch, sh (“box”→“boxes”) · consonant+y becomes -ies (“city”→“cities”)
- Verb forms: drop silent e then +ing (“make”→“making”) · +ed · third-person +s/+es
- Comparatives: +er/+est (“fast”→“faster/fastest”) · consonant+y becomes -ier/-iest (“happy”→“happier”)
- Agent nouns: +er (“teach”→“teacher”) and +or (“act”→“actor”) — one will be wrong for any given word; delete it
- Adverbs: +ly (“quick”→“quickly”) · consonant+y becomes -ily (“happy”→“happily”)
Duplicates and unchanged seeds are removed automatically. Honest limitation: English is full of irregulars (child→children, run→ran, good→better) that no suffix rule can produce — this tool is rule-based, not a dictionary. Review each group and prune the misses.
Everyday uses
- Keyword research — turn 20 seeds into 200 long-tail variants to check in your keyword tool.
- Content clusters — plural and question variants reveal subtopics for supporting posts.
- PPC campaigns — expand match lists with morphological variants cheaply.
- E-commerce SEO — plural forms (“running shoes” vs “running shoe”) often have different search volumes.
- Learning English morphology — the rule column shows exactly how each form was built.