Semrush and Ahrefs are the two all-in-one SEO platforms most agencies and in-house teams end up comparing. Both started as keyword and backlink tools. Both now also sell ways to track how a brand appears in AI answers. That makes the old question, which has the bigger database, only a small part of what you need to decide.
This article is a decision framework plus researched facts about each product. It is not a ranking, and it names no winner. Where a figure comes from a vendor’s own marketing, we say so.
How we researched this: we did not run hands-on tests for this article. It is based on the vendor’s own documentation and public sources, checked on 11 November 2026. Features and prices change, so confirm details on the vendor’s site before you buy.
Key takeaways
- Database size claims are vendor claims. Ahrefs and Semrush each publish large numbers for keywords, backlinks and prompts, and the counting methods differ, so do not treat them as like for like.
- Both vendors now sell AI visibility tracking, but they package and price it differently: Semrush bundles it into Semrush One plans, while Ahrefs sells Brand Radar and custom prompts as separate standalone tools.
- Ahrefs publishes a plan table with dollar prices and limits on its blog, with Standard and above listed as unlimited credits for every active user. Semrush’s plan pages list prices with an annual billing discount and per-plan limits on websites, keywords and prompts.
- Your own project decides this: which sites, how many keywords to track, how many team members, and whether AI visibility matters now.
- Use free trials or free tiers with a fixed set of tasks, and compare the same five tasks in both tools.
Why compare these
Search work now splits between traditional rankings and answers generated by AI systems. Teams want one place to see both, which is why each vendor has added AI features to its core product. If your job involves briefs, content refreshes and reporting, our guides to the AI SEO content workflow and what to include in content briefs show where such tools fit.
A note on company news. Ahrefs’ own comparison page says it has been self-funded since 2011 and says Semrush “got acquired by Adobe.” That is a competitor’s statement on a marketing page, and we could not confirm it from a neutral source during this research. If ownership matters to you, for example for contract or data reasons, check it directly.
Quick overview table
| Item | Semrush | Ahrefs |
|---|---|---|
| Product structure | Modular toolkits; Semrush One bundles SEO and AI Visibility; Enterprise has three modules | Single platform with Free, Starter, Lite, Standard, Advanced and Enterprise plans, plus standalone tools |
| Free option | Free account with capped daily queries; most toolkits have a 7-day trial | Free plan with 6 core tools |
| AI visibility | AI Visibility Toolkit and Semrush One plans | Brand Radar and custom prompt tracking (standalone, paid separately) |
| Claimed keyword database | 28B+ keywords (own page); 26.7B (Ahrefs’ page about Semrush) | 28.7B filtered from 110B discovered (own pages) |
| Claimed backlink data | 43T+ backlinks (own page) | 35T live backlinks (Ahrefs’ claim); says Semrush figure includes dead links |
| Crawler | Not described on pages we read | AhrefsBot, claimed over 8 billion pages a day |
| API and MCP | MCP access listed on Starter; advanced API on Advanced | API v3 and an MCP server |
Criteria that matter
Use criteria that follow your work, as described in our guide to comparing AI tools side by side fairly.
- Data fit: accuracy and coverage for your countries and languages. Only a test on your own keywords shows this.
- Workflow fit: keyword research, rank tracking, audits, content tools, local SEO and PPC research.
- Limits: number of projects or sites, tracked keywords, crawl credits, users and historical data.
- AI visibility: which AI platforms, how many prompts, how often updated.
- Reporting and API: exports, white label reports, programmatic access.
- Total cost: base plan plus add-ons, for the team size you actually have.
Data and how it is collected
Ahrefs
Ahrefs describes AhrefsBot as working like a search engine crawler: it starts from known URLs, schedules crawls, downloads pages respecting robots.txt, parses links and metadata, and feeds an index that powers its reports. It says it shows live link data plus links deleted in the last 60 days. It claims AhrefsBot visits over 8 billion pages every 24 hours, updates its index every 15 to 30 minutes, and ranks as the most active SEO crawler and the eighth most active overall according to Cloudflare Radar. These are Ahrefs’ own claims without independent verification on the page.
For keywords, Ahrefs’ Brand Radar methodology post (published 29 October 2025, updated 26 February 2026) says its keyword database holds about 110 billion discovered keywords, about 28.7 billion of which have positive search volume.
Semrush
Semrush’s “What is Semrush?” page claims roughly 17 years of ongoing web crawling, 289M+ prompts, 28B+ keywords, 43T+ backlinks and 800M+ domain profiles. As with Ahrefs, these are marketing figures. Ahrefs’ comparison page lists a different Semrush keyword number (26.7B) and notes that Semrush’s 43T backlink total includes dead backlinks. Neither vendor’s page gives a method that would let you compare the numbers directly.
| Claim | Source type | Our reading |
|---|---|---|
| Larger live backlink index | Ahrefs marketing page | Competitor claim, not verified |
| 43T+ backlinks | Semrush “What is Semrush?” page | Vendor claim; Ahrefs says it includes dead links |
| 28B+ vs 28.7B keywords | Each vendor’s page | Counted differently; not comparable |
| Index updated every 15 to 30 minutes | Ahrefs academy page | Vendor claim |
The sensible response to all of this is to ignore the headline totals and test the metrics you will use, for example search volume, keyword difficulty and referring domains for ten pages you know well.
Feature coverage
Semrush’s documentation lists keyword research and rank tracking with daily position changes by device and location; AI search visibility across chatbots such as ChatGPT, Gemini and Perplexity; competitor analysis of organic and paid strategies; site audits covering indexing, broken links, speed and Core Web Vitals; backlink analysis with toxic link detection; content tools for topic clusters, briefs and draft scoring; local SEO management; PPC research; and automated white label reports that combine its data with Google Analytics and Search Console. Optional add-ons include Local and Content toolkits.
Ahrefs’ documentation lists core tools within plans (limits such as Rank Tracker keywords, Site Audit crawl credits, Portfolio URLs and historical data), an AI Content Helper, Report Builder and Web Analytics, plus add-ons for extra users, projects and export rows. Its help centre also documents an API and an MCP server for connecting data to AI assistants.
| Capability | Semrush documents | Ahrefs documents |
|---|---|---|
| Rank tracking | Daily positions by device and location; keyword limits by plan | Rank Tracker with keyword limits by plan (50 to 10,000) |
| Site audit | Indexing, links, speed, Core Web Vitals, AI crawler checks | Crawl credits per plan; always-on audit claimed on its comparison page |
| Content tools | SEO Writing Assistant, Topic Research, content toolkit add-on | AI Content Helper, sold as a standalone add-on |
| Local SEO | Google Business Profiles, listings, reviews, map pack tracking | Not confirmed from pages we read |
| PPC research | Competitor ads, spend estimates, paid keywords | Paid pages data exists in its tools; plan detail not confirmed |
| Reporting | White label reports with Google data | Report Builder, sold per project |
AI visibility tracking
This is the area changing fastest, so read dates carefully.
Ahrefs Brand Radar
According to Ahrefs’ methodology post, Brand Radar covers ChatGPT, Perplexity, Gemini, Microsoft Copilot, Google AI Overviews and Google AI Mode, and its monthly volume list also includes Grok. Queries come from Google’s People Also Ask and Ahrefs’ keyword database, expanded into sub-questions, then run through the free public interfaces of each platform. Raw responses are stored so users can search them for citations and mentions. ChatGPT, Perplexity, Gemini and Copilot data refresh monthly with a 90 day window, while AI Overviews and AI Mode update continuously.
Semrush AI Visibility Toolkit
Semrush’s page describes an AI Visibility Score, Competitor and Prompt Research, Brand Performance (share of voice, sentiment, narratives), Prompt Tracking and an AI Search Site Audit that checks for technical issues that could block AI crawlers. Prompt Tracking covers Google AI Mode and ChatGPT per that page, while Semrush One’s product page lists Google AI Overviews, AI Mode, ChatGPT, Gemini and Perplexity. Update frequency per the page: Visibility Overview, Competitor Research and Prompt Research update daily on a rolling basis; Brand Performance updates weekly; Prompt Tracking updates daily.
The two pages for Semrush list slightly different platform coverage, which suggests packaging differs by plan or changed over time. Ask Semrush which platforms your exact plan covers.
| Question | Semrush | Ahrefs |
|---|---|---|
| Platforms (per vendor pages) | Google AI Mode, ChatGPT; One page adds AI Overviews, Gemini, Perplexity | ChatGPT, Perplexity, Gemini, Copilot, AI Overviews, AI Mode |
| Refresh | Daily for prompt tracking; weekly for brand performance | Monthly for chat platforms; continuous for Google AI features |
| Custom prompts | Prompt limits per plan (for example 50, 100 or unlimited on Semrush One tiers) | Separate custom prompt plans sold by check volume |
Whichever you choose, remember that AI answers vary from run to run. Treat visibility scores as directional, and confirm important findings by reading the actual answers. Our guide on how to choose an AI tool covers why.
Pricing models
Prices below were read on 11 November 2026 and are in US dollars. Confirm on each vendor’s site, and see how to read an AI tool’s pricing page for traps such as annual billing and add-ons.
Ahrefs (official blog pricing article, published 9 March 2026, modified 2 October 2026)
| Plan | Price | Selected limits |
|---|---|---|
| Starter | $29/month | 100 credits, 1 unverified project, 50 Rank Tracker keywords |
| Lite | $129/month | 5 unverified projects, 2 extra users, 750 Rank Tracker keywords, 150 AI prompt checks |
| Standard | $249/month | Unlimited credits, 20 projects, 5 extra users, 2,000 keywords, 300 AI prompt checks |
| Advanced | $449/month | Unlimited credits, 50 projects, 10 extra users, 5,000 keywords, 600 AI prompt checks |
| Enterprise | From $1,499/month or $4,490/year | 100 projects, 10,000 keywords, 2,500 AI prompt checks |
Every paid plan except Starter can be bought annually with two months free. Brand Radar is listed from $199 a month per AI platform, or $50 a month for custom prompts, and custom prompt plans are Basic $50 (2,500 checks), Growth $100 (7,000) and Scale $250 (25,000). Other standalone products include AI Content Helper at $99 a month and Report Builder at $99 a month per project. The article is inconsistent on Lite’s credits (500 in one place, 1,000 in another), and Ahrefs’ help article of 23 September 2026 also shows conflicting Lite figures, so confirm.
Semrush (official knowledge base, no pricing date shown)
| Plan | Price when billed annually, per month | Selected limits |
|---|---|---|
| Free | $0 | 1 demo project, 10 reports a day |
| SEO | $117.33 (list $139 monthly) | 5 websites, 500 keywords tracked daily |
| Starter | $165.17 (list $199 monthly) | 5 websites, 500 keywords, 50 AI prompts daily, 1 domain for AI brand performance |
| Pro+ | $248.17 (list $299 monthly) | 15 websites, 1,500 keywords, 100 prompts daily |
| Advanced | Custom, demo required | 40+ websites, 5,000+ keywords, unlimited prompts |
A separate Semrush page for the standalone AI Visibility Toolkit lists a base plan at $99 a month with no free trial, one project and 25 tracked prompts, with add-ons such as extra Brand Performance domains at $99 each and 50 extra prompts at $60 a month. Because that page and the plan table above differ in structure, confirm which plan you are actually quoted.
These are not like for like. Ahrefs’ lowest paid plans use credits and per-plan project limits, with unlimited credits from Standard, and Semrush counts websites, tracked keywords and prompts. Compare cost for your real project size, including the number of seats.
Privacy and data
SEO tools mainly handle public web data, but you may connect Google Search Console, Google Analytics, ad accounts or client domains. We did not read either vendor’s privacy policy or security page during this research, so we cannot summarise their data practices. Before connecting client accounts, check data processing terms, who can access shared projects, how exports are handled, and whether your agency contract allows third-party tools. See how to protect company data when using AI tools for a checklist.
Ahrefs notes that its Brand Radar queries the free public web interfaces of AI platforms. That is a data source detail worth understanding, because it means results reflect public interface behaviour, which can differ from API or logged-in experiences.
Who each suits
| If you need | Documented fit |
|---|---|
| A modular toolkit that also covers local SEO, PPC research and white label reporting | Semrush documents all three in one platform |
| Unlimited credits and per-plan limits focused on rank tracking, audits and historical data | Ahrefs documents these as plan limits, with unlimited credits from Standard |
| AI visibility as an add-on, priced separately | Ahrefs sells Brand Radar and custom prompts standalone |
| AI visibility bundled into one subscription | Semrush One combines SEO and AI Visibility toolkits |
| Enterprise multi-brand AI tracking | Semrush mentions an Enterprise AIO module; Ahrefs Enterprise lists 2,500 prompt checks |
This is a “best for X if Y” reading of documents, not a score. A small agency with several local clients may care most about local and reporting features, while an in-house content team may care most about rank tracking history and keyword data.
How to run your own test
- Choose one site you know well, ideally with Search Console data to compare against.
- Take ten keywords and ten competitor pages. Record search volume, difficulty, referring domains and ranking positions in both tools.
- Run one site audit in each and see which findings you agree with after checking manually.
- Set up the same ten AI prompts in each, if your plan allows, and compare the answers shown against the real AI answers.
- Export a report and check how much editing it needs before a client would see it.
- Price the exact plan and add-ons you would need, for your team size.
Our guide to testing an AI tool before you pay covers the general method.
Decision checklist
- Do the plan limits fit your number of sites, keywords and users?
- Is AI visibility included, or an extra you must price?
- Do you know which AI platforms your plan covers and how often they refresh?
- Have you checked the data on your own keywords, not just headline totals?
- Do you need local SEO, PPC research or white label reports?
- Have you read the data terms before connecting client accounts?
- Do you know the cancellation and annual billing terms?
Frequently asked questions
Which has the bigger database?
Both claim very large numbers, counted differently, and we could not verify either. Test your own keywords instead.
Do both track AI visibility?
Yes. Ahrefs offers Brand Radar and custom prompts as standalone tools, and Semrush offers an AI Visibility Toolkit and Semrush One plans. Platform coverage and refresh rates differ.
Is there a free option?
Ahrefs lists a Free plan with 6 core tools. Semrush lists a Free account with capped daily queries and a 7-day trial on most toolkits.
Is Semrush owned by Adobe?
Ahrefs’ marketing page says so. We could not confirm it from a neutral source in this research, so verify with Semrush if it matters to you.
What does an AI visibility score really tell me?
It estimates how often a brand appears in sampled AI answers. Both tools sample prompts, and answers vary, so treat scores as directional and read real answers too.
Can I use either for several clients?
Both document project or site limits and team users by plan, and Ahrefs lists extra users as add-ons. Check seat and project limits against your client list.
Conclusion
Semrush and Ahrefs overlap heavily, so the decision rests on plan limits, packaging of AI visibility, workflow breadth and how each performs on your own keywords. Ignore headline database claims, test the same tasks in both, and price the plan you will really need. Start with how to choose an AI tool and how to compare AI tools side by side fairly.
Sources
- Ahrefs: Ahrefs pricing (published 9 March 2026, modified 2 October 2026), accessed 11 November 2026
- Ahrefs help: difference between subscription plans (23 September 2026), accessed 11 November 2026
- Ahrefs: Brand Radar methodology (updated 26 February 2026), accessed 11 November 2026
- Ahrefs Academy: crawler and index, accessed 11 November 2026
- Ahrefs: Ahrefs vs Semrush (vendor marketing page), accessed 11 November 2026
- Semrush: Semrush One vs SEO Toolkit, accessed 11 November 2026
- Semrush: What is Semrush One?, accessed 11 November 2026
- Semrush: What is Semrush?, accessed 11 November 2026
- Semrush: AI Visibility Toolkit, accessed 11 November 2026
