Key takeaways
- Semrush: $99 a month per domain, billed annually. Ahrefs: from $199 a month per AI index (October 2026).
- Both show raw AI answers. In the docs we read, only Semrush covers sentiment, and only Ahrefs covers Copilot below enterprise level.
- Each vendor’s own pages disagree on prompt totals, so treat database sizes as claims.
- Neither suite gives a prioritized fix plan. A specialist tool or an audit fills that gap.
How we checked this: Prices, engine lists and metric definitions checked on Semrush’s and Ahrefs’ own pricing pages and knowledge-base articles on October 11, 2026. Ahrefs’ Brand Radar page showed euro prices, so we used the USD figures from its pricing page and help center. Where the two vendors’ own pages contradict each other, we say so. We did not test either tool hands-on.
AnswerMentions sells its own AI visibility audit, which appears in some comparisons on this page. No vendor paid for placement or reviewed this article before publication.
Semrush AI Toolkit vs Ahrefs Brand Radar: the difference in one table
Semrush’s toolkit costs $99 a month and scores your brand 0–100 against competitors. Ahrefs Brand Radar costs from $199 a month per AI index and counts mentions, citations and impression-weighted share of voice. Both show the raw AI answers. Semrush adds sentiment, and Ahrefs adds Copilot and claims a larger prompt index.
Choose by the suite you already pay for, not by the longest feature list. Because both tools show the answers behind their numbers, the real differences are entry price, sentiment, engines, and whether you would rather read a score or a share of voice.
| Dimension | Semrush AI Visibility Toolkit | Ahrefs Brand Radar |
|---|---|---|
| Entry price | $99/mo per domain, billed annually | $199/mo per AI index, $699/mo all platforms |
| Engines | ChatGPT, Gemini, AI Overviews, AI Mode; Perplexity in Brand Performance | AI Overviews, AI Mode, ChatGPT, Perplexity, Gemini, Copilot; Claude for custom prompts only |
| Headline metric | AI Visibility Score, 0–100 | Mentions, citations, impressions, AI Share of Voice |
| Sentiment | Yes, in Brand Performance | None in the docs we read |
| Refresh | Database reports daily, Brand Performance weekly | Chatbots monthly, AI Overviews every few days |
| Custom prompts | 25 included, tracked daily | Sold as checks, daily, weekly or monthly |
Price: what each add-on costs on top of the suite
Semrush’s toolkit costs $99 a month per domain, billed annually, and its pricing page lists no separate SEO plan as required. Ahrefs Brand Radar costs $199 a month per AI index or $699 for all platforms, and Ahrefs’ own pages disagree on whether a paid base plan is needed. All prices are as of October 2026.
Ahrefs’ pricing FAQ says Brand Radar can be bought standalone with an Ahrefs Free account, but its help center says AI indexes need the add-on on any paid plan. If the help center is right, the cheapest route is a $29 Starter plan plus a $199 index, about $228 a month. If you want Semrush’s SEO tools too, Semrush One starts at $199 a month with 50 prompts.
Do not compare prompt counts directly. Semrush counts prompts and adds 50 more for $60 a month. Ahrefs sells custom-prompt packages from $50 a month for 2,500 checks, where one check is one prompt on one platform in one location and a Claude check counts as 8.
Which tracks more prompts in ChatGPT and other engines?
Ahrefs claims the larger prompt index: about 29 million ChatGPT prompts and 470M+ across its engines. Semrush cites 317M+ prompts and responses across four engines but publishes no ChatGPT-only count we could find. For prompts you choose yourself, Semrush Base tracks 25 daily, while Ahrefs sells checks.
Treat both totals as vendor claims. Ahrefs’ product page says 470M+ prompts, while other Ahrefs pages say anything from 150M+ to 476M+. Semrush’s figure runs from 26M+ on its free checker to 317M+ in its knowledge base. A bigger index also does not help a small brand, since Ahrefs says its index suits brands with real search demand.
Collection method matters more than the headline. Semrush says it captures responses from real requests rather than LLM APIs. Ahrefs runs prompts in free public web interfaces and refreshes chatbots monthly on a 90-day window. It lists Grok, but says it cannot currently collect new Grok data.
How each calculates AI visibility
Semrush scores your brand 0–100 against competitors using its prompt database, and tracks your own prompts separately. Ahrefs documents no single score. It counts mentions and citations, then weights AI Share of Voice by impressions, which are Google search volume multiplied by a per-platform usage ratio.
Semrush’s two score definitions differ: one benchmarks you against the competitor median, the other combines topic coverage and mention consistency, with unpublished weights. Our Semrush toolkit review also explains why Position Tracking’s “visibility” percentage is a different metric.
Ahrefs counts a mention once per AI response. It estimates impressions by multiplying each prompt’s parent-keyword volume by a per-platform ratio: 0.115 for ChatGPT, 0.011 for Gemini, 0.01 for Perplexity, 0.0033 for Copilot. Ahrefs itself calls this “a modeling choice, not a measured relationship”. To work backward from mentions to a score, read our Ahrefs Brand Radar review, or plug counts into the AI share of voice calculator.
Which to pick if you already use Semrush, Ahrefs, or neither
Semrush users should buy the Semrush toolkit, and Ahrefs users should buy Brand Radar, because matching your suite saves a second login and billing relationship. With neither, try the free checkers first, then choose Semrush for the $99 entry point and sentiment, or Ahrefs for Copilot and no cap on brands.
Sentiment is the clearest split. Semrush documents favorable-versus-general sentiment in Brand Performance, while the Brand Radar docs we read describe no native sentiment metric. Agencies with many client brands will weigh that against Ahrefs having no cap on brands or domains.
- Semrush shop: buy the toolkit. It costs less to enter and each extra Brand Performance domain is $99 a month.
- Ahrefs shop: buy Brand Radar if you need Copilot or want Reddit and YouTube data (both in beta). Confirm the base-plan rule with Ahrefs first.
- Neither: run both free checkers. Semrush’s allows 3 runs a day without registering. Ahrefs’ needs no signup and shows the top 5 results per section.
When a specialist tool beats both
A specialist tracker beats both when you want more tracked prompts for the money or a workflow built around diagnosis. As of October 2026, Peec AI starts at $95 a month on monthly billing for 50 prompts, and Profound lists a free trial and custom enterprise pricing. Check them before you sign an annual add-on.
Peec AI’s Starter plan drops to $80 a month billed annually (USD as shown outside Europe) and includes daily tracking, unlimited team users and three models of your choice. Profound shows no self-serve paid tier today. For wider comparisons, see Semrush toolkit alternatives and Ahrefs Brand Radar alternatives.
Neither suite hands you a prioritized fix plan for answers where AI names a rival instead of you. AnswerMentions offers a free AI visibility audit that asks AI the questions your buyers ask and shows which brands get named instead of you. It also offers a one-time report with a prioritized fix plan. Use that as the diagnosis step, then track the result in the suite you own.
Reader questions
Frequently asked questions
Is Ahrefs Brand Radar worth paying for?
Yes, if you already use Ahrefs, have real search demand for your brand, and want Copilot or Reddit visibility and volume-weighted share of voice. Skip it if you are a small brand on a tight budget: entry is $199 a month per AI index, chatbots refresh monthly, and the Brand Radar docs we read describe no sentiment metric.
Which tool tracks more ChatGPT prompts?
Ahrefs lists about 29 million ChatGPT prompts in its index. Semrush cites 317M+ prompts across four engines and we found no ChatGPT-only count. For prompts you choose yourself, Semrush Base tracks 25 daily, while Ahrefs Lite includes 150 checks a month. Both totals are vendor claims.
Can I use custom prompts in either tool?
Yes. Semrush’s Prompt Tracking runs your own prompts daily, with 25 on the $99 toolkit. Ahrefs’ Custom Prompts cover every platform plus Claude, daily, weekly or monthly. One Ahrefs check is one prompt on one platform in one location, and a Claude check costs 8 checks.
Do I need a Semrush or Ahrefs subscription first?
Not for Semrush: the $99 toolkit has its own AI Visibility tab and checkout, and no separate SEO plan appears to be required. For Ahrefs the answers conflict. The pricing FAQ says standalone with an Ahrefs Free account, while the help center says an add-on on any paid plan. Ask Ahrefs before you pay.