Content optimization / head-to-head
Clearscope vs Surfer SEO
Surfer SEO's content score did not predict where a page ranked: ρ -0.102. Clearscope's correlation was scored against its own competitor table, not the frozen Google (us) top 10. Both give you a term list.
Clearscope's free trial allows 3 reports and each keyword costs one, so those 3 were the whole budget. Every Clearscope figure here rests on 3 keywords, run 2026-08-20. Surfer SEO ran 20.
The run did produce a correlation: ρ 0.108, scored against its own competitor table. The column is measured against the frozen Google (us) top 10, so printing that figure there would change what the column means.
So the table below holds the measures both runs share plus the ones only one side has, with the empty cells marked not tested. Counts and dates stay on the side that produced them.
Every number here comes from our own runs, not from either vendor, and is read straight out of the test report it came from. The exception is the price: no run paid for that tier, so it was read off the vendor's billing page on the date shown in the cell. How each one is measured is set out in our methodology.
Side by side
| Measurement | Clearscopepilot, n = 3 | Surfer SEO |
|---|---|---|
| Score ↔ rank (ρ)Mean Spearman between the tool's content score and real Google position | —not tested | -0.10296 pages · 2026-08-24 |
| Term precision@30Of the top 30 terms it suggests, how many the ranking pages actually share | 0.203 keywords · 2026-08-20 | 0.1620 keywords · 2026-08-24 |
| SERP overlapDomains its own top 10 shares with the real Google (us) top 10 | —not tested | 85%20 keywords · 2026-08-24 |
| Cheapest paid planCheapest paid tier, US dollars per month | $129/mobilling page, 2026-08-20 | —not tested |
← swipe the table sideways for the rest of the columns
The two runs did not cover the same keywords. Clearscope ran 3 keywords, Surfer SEO 20 (keywords-v1 ids 1-3 against keywords-v1). The term and SERP rows use the same ground truth on both sides; the score-to-rank row does not: Clearscope's correlation was scored against its own competitor table, not the frozen Google (us) top 10. The keyword sets differ and so does that answer key, so this is not a head-to-head. Read each column as its own result.
Who each one suits
Nothing we measured sets Clearscope apart from Surfer SEO.
Surfer SEO's content score told us nothing about where a page would rank, and Clearscope's correlation was scored against its own competitor table, not the frozen Google (us) top 10. If you are choosing on the number a product asks you to work toward, this page gives you one flat result and one blank.
The runs behind this page
- Clearscope review — The widest term coverage we have measured, under letter grades that did not track even its own SERP. Three-keyword pilot; full run pending. Tested 2026-08-20 · pilot, n = 3
- Surfer SEO review — A full 20-keyword run: its content score did not track Google rank under either URL match, and a day-two re-run swapped terms on three of five keywords while the scores held still. Tested 2026-08-24
Build the term list yourself
The ground truth behind both columns is the set of terms the current top-10 pages share. Our Top 10 Term Finder pulls that list for any keyword, free and without an account, using the same extraction that produced the numbers above.