Best SEO tools in 2026

Software for keyword research, backlink analysis, rank tracking and site audits — and, since 2025, tracking how a brand appears in AI answers from ChatGPT, Perplexity and Google's AI Overviews. The category splits between full suites and lighter, cheaper specialists.

4Tools compared
4Use cases
1With free plans
5Cited sources

The ranking

# Tool Starting price Best for Score
1 Semrush
Top pick
£113/mo Teams that want every SEO and AI-search job in a single suite and can justify the price.
84
Visit
2 Ahrefs Free, then £23/mo
Free tier
Anyone whose SEO work centres on links and competitor research.
81
Visit
3 SE Ranking £95/mo Freelancers and small agencies who want most of a full suite at a fraction of the price.
78
Visit
4 Mangools $61/mo Bloggers and beginners who mainly need keyword research and a simple rank tracker.
62
Visit

Ranked on weighted capability scores, weighted most heavily towards backlink data and rank tracking. Commission is not an input — see methodology.

Best by use case

An overall ranking is a compromise. These reweight the same scores for a specific job, and the top pick is not always the same one.

Head to head

Every tool in detail

1. Semrush

The broadest SEO suite on the market, now bundling AI-search visibility tracking into most plans.

84/100

Strengths

  • +The widest toolset in the category — keyword research, rank tracking, audits, competitor analysis and AI-search tracking in one login.
  • +Every plan includes some AI-search tracking; Starter and above add daily prompt tracking, starting at 50 prompts.
  • +Tracks rankings daily and supports multi-location and device tracking on Pro+ and above.

Limitations

  • Expensive — £113 a month for the entry SEO plan, and extra users cost from £36 a month each.
  • Historical SEO data and content optimisation tools start at Pro+, £242 a month.
  • The sheer number of tools makes it slow to learn for a first-time user.

2. Ahrefs

The SEO suite best known for its backlink index, powered by one of the most active crawlers on the web.

81/100

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.

3. SE Ranking

A capable all-round SEO platform priced well below the big two, with strong rank tracking and AI-search (GEO) tools.

78/100

Strengths

  • +Core gives twice the projects and four times the tracked keywords of Semrush's entry plan (10 and 2,000), for less — £95 a month.
  • +AI-search tracking comes built in: 100 prompts a day on Core, 250 on Growth.
  • +Unlimited keyword, competitor and backlink research on every plan.

Limitations

  • API use is capped — 25,000 credits a month on Core.
  • White-label reporting for agencies is a £49-a-month add-on, annual billing only.
  • Historical data across a project's lifetime needs the Growth plan.

4. Mangools

A set of simple, beginner-friendly SEO tools — best known for KWFinder — at the lowest prices in this comparison.

62/100

Strengths

  • +Built around KWFinder, a dedicated keyword research tool, with rank tracking and backlink lookups alongside.
  • +Annual billing brings the Basic plan to about $38 a month.
  • +A handful of single-purpose tools — KWFinder, SERPWatcher, LinkMiner and others — rather than one sprawling suite.

Limitations

  • There is no full technical site-audit crawler, unlike the three suites here.
  • Monthly billing costs about 60% more than annual — $61 against roughly $38.
  • The refund window is only 48 hours.

Common questions

What is the best SEO tool overall?

On our weighted scoring across every use case in this category, Semrush ranks first with 84/100, ahead of Ahrefs on 81. It leads mainly on rank tracking and site audits.

Is there a free SEO tool?

Yes — Ahrefs offers a free plan. Free tiers differ enormously in what they actually allow, so check the limits rather than the label.

What is the cheapest SEO tool?

Ahrefs at £23/mo (monthly; keyword and competitor research only) has the lowest paid entry point. Prices in different currencies were compared at the European Central Bank reference rate. Cheapest is rarely best value — check what the next tier up costs and what the plan renews at, because that is where most people end up.

Sources & verification

  1. ahrefs.com — checked 23 September 2026
    Ahrefs Free covers data for sites you own; researching competitors needs a paid plan.
  2. api.frankfurter.app — checked 24 September 2026
    European Central Bank reference rate, published via Frankfurter.
  3. mangools.com — checked 23 September 2026
    No free plan, though Mangools publishes several free standalone SEO tools.
  4. seranking.com — checked 23 September 2026
    No free plan; a 14-day free trial with no card required.
  5. semrush.com — checked 23 September 2026
    Free trial available on paid plans; no free plan listed on the pricing page.