SEO tool cost calculator

For each vendor, the calculator walks the self-serve plans from cheapest to most expensive and stops at the first one that meets every input: enough sites, room for every person, and AI visibility or MCP access if you ticked them.

• Seats: Ahrefs and Semrush plans include one user. Extra users cost $40 to $80/mo each on Ahrefs and $45 to $100/mo each on Semrush, depending on the plan. Ahrefs caps extra users per plan; Semrush lists no cap.
• AI visibility: Semrush includes it from Starter ($199/mo). Ahrefs plans track a few AI prompts, and brand research across its prompt database is the Brand Radar AI add-on, from $199/mo. IndexZero includes it from Starter ($29/mo).
• Sites: an Ahrefs project, a Semrush monitored website and an IndexZero project are different things. The calculator counts one site as one of each. Ahrefs only caps projects for sites whose ownership you haven't verified.
• Beyond self-serve: when no plan fits, the card says so and points at the vendor's sales route, such as Ahrefs Enterprise from $1,499/mo with an annual commitment.

All prices are month-to-month. Ahrefs and Semrush both discount annual billing; IndexZero has no annual price, so the calculator doesn't compare annual totals.

A few common setups

• 1 site and 1 person: Ahrefs Lite $129/mo; Semrush SEO $139/mo; IndexZero Free $0/mo.
• 3 sites and 2 people with AI visibility: Ahrefs Lite $368/mo; Semrush Starter $244/mo; IndexZero Starter $29/mo.
• 5 sites and 4 people with AI visibility and agent access: Ahrefs Standard $628/mo; Semrush Starter $334/mo; IndexZero Pro $79/mo.
• 20 sites and 6 people with AI visibility and agent access: Ahrefs Standard $748/mo; Semrush Advanced $1,049/mo; IndexZero Scale $199/mo.

On Ahrefs and Semrush, cost grows with the number of people who log in. A team of four on Ahrefs Lite doesn't fit (Lite allows 2 extra users), so the same work moves to a pricier plan with pricier seats.

Neither pricing page lists a price for an AI agent. Both include MCP access on some plans, and an agent connected that way works within the plan's limits for the account that connected it.

IndexZero prices by usage instead. Every plan includes unlimited members and agents, and the plan sets a monthly credit allowance (30,000 credits on Starter). Adding a teammate or an agent costs nothing by itself; the research they run spends credits.

• Data quotas. Tracked keywords, crawl credits, AI prompts and report rows differ by plan and aren't modeled. IndexZero's credits run out too, and heavy use needs top-ups.
• Index depth and historical data. Ahrefs and Semrush have run their own crawlers and databases for years. IndexZero doesn't claim parity on either.
• Annual discounts, taxes, and add-ons beyond seats and Brand Radar AI.
• Price changes. Every number was checked on 2026-09-15; the sources list links to each pricing page.

• You need years of backlink and ranking history. Ahrefs Advanced keeps five years, and Enterprise keeps all of it.
• Link research is the core of your work and index size decides the result.
• You run a large content program and want editorial tools, briefs and content grading in the same product.
• Your company needs SSO and audit logs. Ahrefs lists both on its Enterprise plan; IndexZero doesn't offer them.

If most of what you use is keyword research, rank tracking, site audits and AI visibility, run your own numbers above and check the quotas that matter to you on each pricing page.