Picking an SEO tool is a two-axis decision: how deep the backlink or keyword index is, and what the bill scales with (credit pool, tracked keywords, site count, or user seat). The five tools here split cleanly along both axes. Semrush is the broadest suite in the cluster — keyword research, rank tracking, backlink analysis, site audit, and content optimizer all in one platform. Entry is $139/mo (SEO tier: 5 sites / 500 keywords), stepping up to Starter $199 / Pro+ $299 / Advanced $549/mo; annual billing saves up to 17% (entry ~$117/mo). Add-ons: users $45/mo, Lead Gen $90/mo, reports $10-20/mo. Ahrefs is the backlink-purist choice: the deepest backlink index in the cluster, priced by credit pool and user seat. Lite $129/mo (5 projects / 750 tracked keywords / 100K crawl credits / 1 user), Standard $249 / Advanced $449 / Enterprise $1,499/mo; annual saves up to 17% (Lite ~$119/mo). A free capped tier exists but has no credit pool. Moz Pro is the most established brand and the cheapest entry point to the big three: $99/mo Standard (1 user / 3 sites / 300 keywords / 400K pages crawled), $179/mo Medium (2 users / 10 sites / 1,500 keywords / 2M pages), $299/mo Large (3 users / 25 sites / 3,000 keywords / 5M pages); annual saves ~20% (Standard $79/mo, billed $950/yr). Enterprise at $49/mo for single-site individual use. No free plan. Screpy is the budget option with a genuinely free tier — one project, 100 rank checks, 100 crawl pages, no card required — then Pro $19/mo (5 projects / 100 rank / 5K crawl / 5 AI prompts / 5 seats), Max $49/mo (15 projects / 3,000 rank / 10K crawl / 50 competitors / backlinks / 15 seats), Ultra $99/mo (50 projects / 5,000 rank / 50K crawl / 100 competitors / 250 AI prompts / 30 seats); annual pricing collapses to ~$6.4 / $15.2 / $29.6/mo. SpyFu is the competitive-ad-intelligence outlier: it pairs paid-search ad history with SEO keyword data, priced by competitor domains and keyword depth. Starter $59/mo (1 competitor / basic keyword data), Advanced $159/mo (3 competitors / full keyword + ad data / API access), Professional $399/mo (10 competitors / unlimited keyword exports / dedicated support); annual saves ~17% (Starter ~$49/mo). No free plan. The real question is whether your workload is index depth (Ahrefs), feature breadth (Semrush), brand-trusted entry (Moz), single-site budget monitoring (Screpy), or competitive ad intelligence (SpyFu). All prices re-checked 2026-09-20, official pricing pages, evidence=research.
Semrush (4.5/5) is the most feature-broad platform: keyword research, rank tracking, site audit, content optimization, local, AI visibility (50-200 prompts), API and MCP in one seat. The cost reflects the breadth: $139/mo SEO entry, $549/mo Advanced for API.
Free tier: No — trial only · 7-day free trial (all tiers)
Paid from: $139/mo (SEO, monthly) (All tiers include AI search visibility tracking. SEO: 5 sites / 500 keywords. Starter: +MCP / 50 AI prompts / 5 sites. Pro+: 15 sites / 1500 keywords / 100 prompts. Advanced: 40 sites / 5000 keywords / 200 prompts + API. Add-ons: users $45/mo, Lead Gen $90/mo, Base Report $10/mo, Pro Report $20/mo. Enterprise custom.)
Semrush is the most feature-broad SEO and digital marketing suite in the cluster - keyword research, rank tracking, site audit, content optimization, local and AI visibility, plus API and MCP access, with the widest add-on ecosystem.
Ahrefs (4.5/5) wins on backlink depth - the second-most active crawler and 10+ year web-scale index. Credit-pool pricing (100K Lite / 500K Standard / 1.5M Advanced) makes heavy projects expensive. $29 Starter is a 1-month trial only.
Free tier: No — trial only · $29 Starter (1 month only, then converts to Lite)
Paid from: $129/mo (Lite, monthly) (Priced by credit pool and user seat. Lite: 5 projects / 750 tracked keywords / 100K crawl credits / 1 user (+2 seats at $40/mo each). Standard: 20 projects / 2000 keywords / 500K credits / 1 user (+5 at $60/mo). Advanced: 50 projects / 5000 keywords / 1.5M credits / 1 user (+10 at $80/mo). API and MCP access on all tiers. Ahrefs Free is a capped free tier with no credit pool.)
Ahrefs is a backlink-driven SEO platform pairing the world's second-most active crawler with rank tracking, keyword research, site audits and AI visibility monitoring, priced by credit pool and user seat.
Moz (4.2/5) is the cheapest entry of the three major SEO suites at $99/mo Standard, with Domain Authority still the most-cited link metric and 2026 AI visibility on every tier. Backlink depth trails Ahrefs.
Free tier: No — trial only · 14-day free trial (Medium tier)
Paid from: $99/mo (Standard, monthly) (Priced by user seats and tracked sites/keywords. Standard: 1 user / 3 sites / 300 keywords / 400K pages crawled. Medium: 2 users / 10 sites / 1500 keywords / 2M pages. Large: 3 users / 25 sites / 3000 keywords / 5M pages. All tiers include AI Visibility Dashboard, 4 tracked AI models. Enterprise at $49/mo for single-site individual use. No free plan.)
Moz Pro is a long-established SEO suite focused on Domain Authority metrics, keyword tracking, site audits and backlink research, now with AI Overviews tracking and AI Visibility Dashboards on every tier.
Screpy (4.0/5) is the only tool with a standing free plan (no credit card) and the cheapest paid entry at $19/mo Pro (~$6.4/mo billed annually). Feature breadth is lighter but the all-in-one dashboard is the right answer for a solo site without a $129/mo budget.
Free tier: Yes · 14-day free trial on paid tiers
Paid from: $19/mo (Pro, monthly) (Genuinely free tier (no credit card): 1 project / 100 rank / 100 crawl pages. Pro: 5 projects / 100 rank / 5K crawl / 10 competitors / 5 AI prompts / 5 seats. Max: 15 projects / 3000 rank / 10K crawl / 50 competitors / 50 AI prompts / backlinks / 15 seats. Ultra: 50 projects / 5000 rank / 50K crawl / 100 competitors / 250 AI prompts / 30 seats.)
Screpy is an AI-powered all-in-one SEO and site monitoring platform combining rank tracking, PageSpeed, uptime, backlinks, AI content generation and AI visibility prompts in one dashboard, with a genuinely free tier.
SpyFu (4.1/5) is the competitor-intelligence specialist at $59/mo Starter. Cleanest teardown UX for what competitors rank for and what ads they run, but no backlinks, no rank tracking, no API below Advanced. Annual figures behind paywall.
Free tier: No — trial only · 14-day free trial
Paid from: $59/mo (Starter, monthly) (Priced by competitor domains and keyword depth. Starter: 1 competitor domain / basic keyword data. Advanced: 3 competitor domains / full keyword + ad data / API access. Professional: 10 competitor domains / unlimited keyword exports / dedicated support. Prices shown behind a paywall; exact annual figures to be confirmed on signup. No free plan.)
SpyFu is a competitive intelligence platform focused on advertising and SEO keyword data - see what keywords competitors rank for, what ads they run and where their traffic comes from - positioned as a lighter, more affordable alternative to Ahrefs or Semrush.
Bottom line: Semrush is the pick for teams and agencies that want the widest suite including AI-search tracking and MCP. Ahrefs is the backlink-depth benchmark. Moz is the value entry to the big three. Screpy is the solo-operator value pick with a genuine free plan. SpyFu is the competitor-intelligence specialist. No tool in the cluster is genuinely free except Screpy.
Semrush (4.5/5) is the widest suite - keyword research, rank tracking, site audit, content, local, AI visibility, API and MCP in one seat. Ahrefs (4.5/5) is the backlink-depth benchmark. The right answer depends on whether breadth or depth is the point.
Screpy - the only tool with a standing free plan (no credit card) and a $19/mo Pro entry (~$6.4/mo billed annually). It is the right answer for a solo site that does not need a $129/mo budget.
Ahrefs - the second-most active crawler in the world with 10+ years of web-scale data. Semrush is a close second on breadth; Moz's Domain Authority remains the most-cited link metric.