Best SEO tools for backlink research
The biggest, freshest backlink index, for finding link opportunities and seeing what competitors earned.
| # | Tool | Starting price | Best for | Score | |
|---|---|---|---|---|---|
| 1 | Ahrefs Top pick | Free, then £23/mo Free tier | Anyone whose SEO work centres on links and competitor research. | | Visit |
| 2 | Semrush | £113/mo | Teams that want every SEO and AI-search job in a single suite and can justify the price. | | Visit |
| 3 | SE Ranking | £95/mo | Freelancers and small agencies who want most of a full suite at a fraction of the price. | | Visit |
| 4 | Mangools | $61/mo | Bloggers and beginners who mainly need keyword research and a simple rank tracker. | | Visit |
Ranked on weighted capability scores, weighted most heavily towards backlink data and keyword research. Commission is not an input — see methodology.
How this ranking was weighted
| Dimension | Weight | Ahrefs | Semrush | SE Ranking | Mangools |
|---|---|---|---|---|---|
| Backlink data | ×4 | 5 | 4 | 3 | 3 |
| Keyword research | ×2 | 5 | 5 | 4 | 4 |
| Site audits | ×1 | 4 | 5 | 4 | 2 |
| Weighted total | 97 | 89 | 69 | 63 |
Capability scores are 1–5 per dimension. Weights reflect what matters for this use case. A tool we have not assessed on a dimension scores 3, not 0.
Why Ahrefs wins here
Strengths
- +Its backlink and site data come from what Ahrefs describes as the world's second-most active web crawler.
- +A genuinely useful free plan for sites you own, and a £23 Starter plan for light keyword research.
- +API and MCP access included on every paid plan from Lite upwards.
Limitations
- −Lite is £99 a month with only six months of historical data and one user.
- −Additional users cost £32–£64 a month each depending on plan.
- −AI prompt tracking is limited — five prompts on Lite, twenty on Advanced.
The case for Semrush
The broadest SEO suite on the market, now bundling AI-search visibility tracking into most plans. Teams that want every SEO and AI-search job in a single suite and can justify the price.
Full Ahrefs vs Semrush comparison →
Common questions
Best SEO tools for backlink research?
Ahrefs scores highest for link building, at 97 out of 100 when weighted for backlink data and keyword research. Semrush is second on 89.
Why is the pick here different from your overall ranking?
Our overall ranking for SEO tools puts Semrush first, because it averages every use case. Weighted specifically for link building, Ahrefs comes out ahead — the biggest, freshest backlink index, for finding link opportunities and seeing what competitors earned.
Sources & verification
- ahrefs.com — checked 23 September 2026Ahrefs Free covers data for sites you own; researching competitors needs a paid plan.
- mangools.com — checked 23 September 2026No free plan, though Mangools publishes several free standalone SEO tools.
- seranking.com — checked 23 September 2026No free plan; a 14-day free trial with no card required.
- semrush.com — checked 23 September 2026Free trial available on paid plans; no free plan listed on the pricing page.