Buying SEO on a near-zero budget comes down to whether the free or entry offer can run a real workflow, and what the bill scales with once it starts moving — credit pool, tracked keyword cap, site count, or user seat. Screpy is the only genuinely free option here and the only one that needs no card: one project, 100 rank checks and 100 crawled pages at $0, then Pro $19/mo (5 projects / 100 rank / 5,000 crawl / 5 AI prompts / 5 seats), Max $49/mo (15 projects / 3,000 rank / 10,000 crawl / backlinks / 15 seats) and Ultra $99/mo (50 projects / 5,000 rank / 50,000 crawl / 100 competitors / 250 AI prompts / 30 seats); annual billing collapses those to roughly $6.4, $15.2 and $29.6 a month. SpyFu is the cheapest paid entry of the five at $59/mo Starter — but the scope is narrow (1 competitor domain, basic keyword data); Advanced $159/mo adds 3 competitors, full keyword and ad data plus API access, and Professional $399/mo unlocks 10 competitors and unlimited exports. No free plan; annual saves about 17%. Moz is the cheapest entry of the big three at $99/mo Standard (1 user / 3 sites / 300 keywords / 400K pages crawled), stepping to $179 Medium (2 users / 10 sites / 1,500 keywords / 2M pages) and $299 Large (3 users / 25 sites / 3,000 keywords / 5M pages); annual saves about 20% (Standard $79/mo, billed $950/yr). There is no free plan. Ahrefs prices by credit pool and seat and is the deepest backlink index in the cluster: Lite $129/mo (5 projects / 750 tracked keywords / 100K crawl credits / 1 user), then Standard $249 / Advanced $449 / Enterprise $1,499; annual saves up to 17%. A capped free tier exists but carries no credit pool. Semrush is the widest suite and the priciest entry at $139/mo (5 sites / 500 keywords), stepping to Starter $199 / Pro+ $299 / Advanced $549; annual saves up to 17%, with add-ons for users ($45/mo), Lead Gen ($90/mo) and reports ($10-20/mo). The practical split: free single-site monitoring (Screpy), cheapest competitive ad intelligence (SpyFu), trusted brand at the lowest big-three price (Moz), backlink depth (Ahrefs), or all-in-one suite breadth (Semrush). All prices re-checked 2026-09-20 against official pricing pages, evidence=research.
The only tool in the cluster with a standing free plan: 1 project / 100 rank tracker / 100 crawl pages, no credit card required. Pro at $19/mo (annual $77/yr = ~$6.4/mo) is the cheapest paid entry in the set.
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.
No free plan - 14-day Medium trial only. Standard at $99/mo is the cheapest entry of Ahrefs, Semrush and Moz, with Domain Authority and AI visibility on every tier.
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.
No free plan - 14-day trial. Starter at $59/mo is the cheapest entry of all five tools for a single competitor domain; annual figures are behind a 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.
No free plan - the $29 Starter is a 1-month trial that converts to $129/mo Lite. Ahrefs Free is a capped free tier with no credit pool. The 100K Lite credit pool is the floor.
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.
No free plan - 7-day trial all tiers. SEO at $139/mo is the floor; the 5-site / 500-keyword cap means real work pushes to Starter at $199/mo or Pro+ at $299/mo.
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.
Bottom line: Screpy is the only genuinely free tool (no credit card, 1 project / 100 rank / 100 crawl). SpyFu at $59/mo is the cheapest paid entry but has the narrowest scope. Moz at $99/mo is the cheapest entry of the big three and carries Domain Authority plus AI visibility. Ahrefs at $129/mo and Semrush at $139/mo are the premium entries. Free-ness and bill-scaling decide; feature depth is secondary.
Screpy is the only tool with a standing free plan (no credit card). Ahrefs has a capped free tier with no credit pool. The big three (Ahrefs, Semrush, Moz) and SpyFu are trial-only.
SpyFu Starter at $59/mo is the cheapest paid entry, but it is a single competitor domain with no backlinks. Moz Standard at $99/mo is the cheapest entry of the big three full platforms.
Screpy free plan: 1 project / 100 rank tracker / 100 crawl pages, no credit card. Ahrefs Free is capped and has no credit pool, so it is not a real workflow tier.