Serper vs SearchAPI.io
Choosing between Serper and SearchAPI.io? Both are search providers you can call through a single Auxiliar key, so the honest answer is usually “use whichever wins the job in front of you” — and with one key and one bill, you don’t have to commit to either.
We ran both on the identical curator-fleet corpus. Serper leads on structured Google/SERP results (9.56 vs 9.02). On the headline test (structured Google/SERP results), Serper scored 9.56/10 (quality 1.00) versus 9.02/10 for SearchAPI.io. The full measured breakdown is below.
Measured, side by side
Composite score /10 on each shared capability, from the Auxiliar curator fleet — same corpus for both.
| Capability | Serper | SearchAPI.io | Winner |
|---|---|---|---|
| SERP verticalsQuality | 9.561.00 · #1/4 | 9.020.98 · #2/4 | Serper |
| SearchRecall@10 | 7.240.57 · #3/11 | 6.440.57 · #8/11 | Serper |
Serper — choose if
You want the cheapest, fastest Google grounding and will synthesize results yourself.
SearchAPI.io — choose if
You want SerpApi-compatible JSON at a lower price, with pay-per-success billing.
Serper — avoid if
You need multi-engine coverage, rich-SERP features, or built-in content extraction.
SearchAPI.io — avoid if
You depend on large Google result pages (num silently capped at 10 since Sept-2025).
One key. Every provider on this page.
Stop juggling signups and invoices. One Auxiliar API key calls all of them — upstream keys injected server-side, usage billed to a single balance. Swap the base URL and go.
curl https://api.auxiliar.ai/serper/search \ -H "Authorization: Bearer $AUXILIAR_API_KEY" \ -H "Content-Type: application/json" \ -d '{"q": "latest ai agent news"}'