AI SDR: What It Is, How It Works, What It Costs (2026)
A human SDR spends the day finding names, writing cold emails, chasing replies and trying to land a meeting on an account executive’s calendar. An AI SDR is software sold to do that job, or parts of it, around the clock.
The gap between the demo and the results comes down to which parts it actually does well.
The quick answer: An AI SDR (AI sales development representative) is an AI agent that does top-of-funnel sales work: it finds and researches leads, writes and sends outreach, follows up, answers replies and books meetings. Autonomous agents run from about $94 a month for self-serve tools to $3,750 and up for enterprise ones, against roughly $114,000 a year for a human SDR once benefits are counted. Carly is the pick for teams whose bottleneck is replies, follow-up, speed to lead and booking: it runs sequences from your reps’ own Gmail and Outlook mailboxes, drafts every reply in one shared team inbox, reaches new inbound leads within minutes and books them on the right rep’s calendar. Free Zapier-style workflows; AI agents from $35/month.
AI SDRs at a glance
US list prices from each vendor’s site, checked October 4, 2026.
| Kind | Examples | What it does | Entry price |
|---|---|---|---|
| Reply, follow-up and booking agent on your own mailboxes and phone | Carly | Sequences from reps’ Gmail and Outlook, AI-drafted replies in a shared inbox, inbound leads reached in minutes by email, text or call, booking, CRM | Free Zapier-style workflows; AI agents from $35/month. Teams set up on a short call |
| Autonomous outbound agents | AiSDR (Ami), 11x (Alice), Artisan (Ava), Reply.io (Jason), Instantly’s AI agents, Amplemarket (Duo) | Finds leads, researches, writes and sends, answers replies, books | Instantly bundle $94/mo, AiSDR $250/mo, Reply.io AI SDR $500/mo on an annual commitment, 11x from $3,750/mo billed annually, Artisan quote only |
| Engagement platforms adding AI | Apollo, Outreach, Salesloft | Reps run sequences; AI agents research, write and prioritize | Apollo free or $49/seat/mo billed annually; Outreach and Salesloft quote only |
| Human SDR | Your hire | All of it, plus judgment and live calls | About $80,000 OTE, roughly $114,000 a year with benefits |
For the ranked, tool-by-tool comparison, see our best AI SDR tools list.
What an AI SDR is
An AI SDR is an AI agent that takes over some or all of a sales development rep’s job. A sequencer that sends emails you wrote isn’t one. The agent part is that it decides what to write, who to chase and what to say back. An SDR’s job is really seven jobs, and AI is much better at some than others:
| SDR job | What AI does well today | Where a human still wins |
|---|---|---|
| Find and research leads | Pulls lists from databases and signals, reads a company’s site and news in seconds | Knowing which accounts matter this quarter |
| Write and send outreach | First drafts at volume, a relevant opening line per lead | A real point of view; AI copy starts to sound alike |
| Follow up | Never forgets, stops the moment someone replies | Little: this is AI’s job now |
| Handle replies and objections | Sorts replies by intent, drafts answers to common questions within minutes | Price pushback, an annoyed prospect, anything political |
| Book meetings | Offers real open times and sends the invite | Little, if it can read every calendar |
| Update the CRM | Logs every touch and moves the deal | Nothing; reps hate this part |
| Respond to inbound fast | Emails, texts or calls a new lead within minutes, at any hour | Live discovery once the buyer is engaged |
Speed to lead is where the gap is widest. In Harvard Business Review’s 2011 study, 23% of 2,241 audited US companies never answered a web lead at all, and across 1.25 million leads, firms that reached a lead within an hour were nearly seven times as likely to qualify it as those that waited an hour longer. Our sales follow-up statistics collect the rest.
How an AI SDR works: one lead from first touch to booked meeting
Josh Whitaker runs sales at a 20-person freight software company, and his reps, Emily Parker and Michael Hayes, pull leads from Apollo. Here’s one prospect, Claire Donovan, a VP of operations at an apparel brand, on Carly:
- The signal. Claire’s company posts a job for a logistics analyst. Emily adds her from Apollo, and Carly enriches the record with Apollo and People Data Labs and reads the company’s recent news.
- The sequence. A four-step sequence sends from Emily’s own Outlook mailbox, inside her sending window and daily cap. Follow-ups go out as replies in the same thread, so Claire sees one conversation.
- The reply. On day eight Claire writes: “We’re locked in with our current vendor until March, but send me what this costs.” The sequence stops on its own. Carly labels the reply interested and drafts an answer in the shared team inbox. Emily changes one line and sends.
- The booking. Claire asks for 30 minutes next week. Carly checks all of Emily’s Google and Microsoft calendars at once, offers three times in Claire’s time zone and sends the invite.
- The CRM. The deal lands in HubSpot with the thread attached. After the call, Carly reads the Gong notes, sends Claire the follow-up and moves the deal stage.
That evening, a demo request arrives at 7:40pm. A routing rule assigns it to Michael, the lead gets an email from his address and a text from the business number within minutes, and the AI voice agent calls with the form answers in hand and books a slot on Michael’s calendar.
An autonomous outbound agent runs the first two steps differently: it picks Claire from its own database, sends from domains it bought and warmed, and often answers her itself. Want to see the reply-to-booking half on your team’s own mail? Book a call with the Carly team.
Kinds of AI SDR, Carly first
1. Reply, follow-up and booking agents: Carly
Carly is an AI assistant for sales teams that works from the mailboxes, calendars, phone line and CRM you already use. It’s built for the part of outbound where most pipeline quietly dies: the reply, the follow-up, the inbound lead at 7:40pm and the booking.
- Sequences from your own mailboxes. Multi-step sequences send from each rep’s real Gmail and Outlook accounts and stop when the person replies (in any thread) or books. Daily caps, sending windows and unsubscribe headers are built in.
- One shared team inbox. Every rep’s mailboxes, plus the team’s calls and texts, in one place, with assignments, notes, reminders and an “Awaiting reply” view.
- Every reply drafted and sorted. Carly labels replies interested, not interested or out of office, and drafts the answer. Review and send, or let the agent send on its own.
- Speed to lead. Routing rules assign each new lead to an owner or a team, and the lead gets an email, a text or both within minutes from your own address and business number.
- Booking. The right rep’s calendar across all their Google and Microsoft accounts, or a booking page.
- A CRM that stays current. Use the built-in CRM for lead statuses, weighted pipeline and reports by owner, or keep HubSpot, Salesforce, Pipedrive, Close or Attio and Carly logs there.
- Your stack stays. Carly connects to thousands of apps, including Apollo, Hunter, Lusha, Instantly, Slack and Gong, so you can keep Apollo for data or Instantly for volume and let Carly take over at the reply. Steps that need no AI run as free Zapier-style workflows.
Price: Free Zapier-style workflows; AI agents from $35/month. Carly for teams is set up with you on a short call, including high-volume cold programs across many domains: book it here.
2. Autonomous outbound agents
- AiSDR (Ami): signal-based prospecting, researched email and LinkedIn sequences, replies within minutes. Solo is $250/mo month to month; Explore ($900) and Scale ($2,500) are quarterly contracts. See our AiSDR review and AiSDR alternatives.
- 11x (Alice): an “outbound digital worker” with managed Gmail mailboxes, warmup and CRM sync, plus Julian for inbound. Growth from $3,750/mo billed annually; annual contracts are the default.
- Artisan (Ava): an “AI BDR” with a 250M+ contact database, autonomous replies and booking. Every plan is quoted on a sales call.
- Reply.io (Jason): an AI SDR inside Reply.io’s multichannel platform, from $500/mo on an annual commitment.
- Instantly’s AI agents: the AI Sales Agent finds leads, writes, follows up and books; the AI Reply Agent answers replies. Bundles from $94/mo billed monthly. See our Instantly review and Instantly alternatives.
- Amplemarket (Duo): an AI sales agent that watches target accounts for buying signals and drafts multichannel sequences for reps to approve. Startup is $600/mo on an annual term with two users.
3. Engagement platforms adding AI
- Apollo: a contact database and sequencer whose agents research, build lists, write, follow up and book. Free plan; Basic $49/seat/mo billed annually.
- Outreach: sequences, deals and forecasting, with AI agents working accounts alongside reps. Quote only (Outreach alternatives).
- Salesloft: cadences with AI agents, merged with Clari in December 2025. Quote only (Salesloft alternatives).
What an AI SDR costs
Vendors bill per researched contact (AiSDR, 11x), per active contact (Reply.io) or per bundle plus credits (Instantly), and contract length matters as much as the sticker. AiSDR’s Explore is $900 a month on a quarterly contract, so $2,700 minimum. 11x’s Growth plan lists $3,750 a month billed annually, while the same page’s FAQ says $36,000 a year.
A human SDR. The Bridge Group’s 2025 SDR report (351 B2B companies) puts median on-target earnings at $80,000: $55,000 base and $25,000 variable. Benefits are 30% of private-industry compensation cost (BLS, June 2026), which takes that to about $114,000 a year, or $9,500 a month, before data and sequencer seats and a manager’s time. The same report found a 3-month average ramp, 1.9-year average tenure and 40% median annual attrition. At the median quota of 10 meetings held a month, that’s about $950 a meeting, and only 60% of SDRs hit quota.
The hidden costs of an autonomous agent:
- Domains and mailboxes. Cold volume goes out from secondary domains to protect your main one. Reply.io sells new domains from $6 a year plus $5 a mailbox a month.
- Warmup time. AiSDR says it takes 30+ days to get several inboxes ready for full volume, inside a contract you’re already paying for.
- Data credits. Lead lookups and AI actions often draw from a separate credit balance (Instantly, Apollo, Reply.io).
- A minder. Someone still has to keep targeting inside your ICP and read what the agent sends.
Carly sends from the mailboxes your reps already have, so replies and follow-ups come from addresses your prospects know. Free Zapier-style workflows; AI agents from $35/month.
AI SDR vs human SDR
| AI SDR | Human SDR | |
|---|---|---|
| Cost | $94 to $3,750+ a month | About $9,500 a month with benefits |
| Ramp | Weeks, mostly mailbox warmup | 3 months on average |
| Hours | Around the clock | Business hours |
| Volume | Hundreds to thousands of contacts a month | 10 meetings held a month at median quota |
| Judgment | Follows instructions; can hallucinate | Reads the room, handles odd objections |
| Live calls | Mostly left to reps, or AI calls to leads who opted in | Yes |
| Turnover | None, but quarterly or annual contracts | 40% a year |
What vendors claim and what buyers report
Vendor claims. AiSDR’s homepage promises 1 to 3 qualified meetings per 100 leads, 1 to 2 weeks to a first meeting and 12,000 meetings booked for clients in 2025. 11x’s pricing page says a fully loaded SDR costs $8,000 to $12,000 a month. These are the vendors’ own numbers.
What buyers report. In March 2025, TechCrunch reported that most of 11x’s early customers used three-month break clauses to walk away (one employee put it at 70 to 80%), citing emails that didn’t work as expected and hallucinations; 11x said performance “ultimately relies on the quality of user input.” AiSDR reviewers describe a slow first month while mailboxes warm. In sales subreddits, the recurring complaints are meetings booked off a two-line reply with prospects who show up cold, follow-ups that turn generic, and no way to see why the agent did what it did.
Deliverability and brand risk. Since February 2024, Gmail requires every sender to use SPF or DKIM and keep spam complaints below 0.3%, and anyone sending more than 5,000 messages a day to Gmail also needs DMARC and one-click unsubscribe on marketing mail. An agent that floods your main domain can push your reps’ everyday email into spam, and a wrong fact about a prospect’s business goes out under your company’s name. Keep human review on replies until you trust the drafts.
Compliance basics: CAN-SPAM, GDPR and TCPA
A plain summary, not legal advice.
- CAN-SPAM (US email). There’s no business-to-business exception. Commercial email needs honest headers and subject lines, your physical postal address and a working opt-out honored within 10 business days. The FTC puts penalties at up to $53,088 per violating email.
- GDPR (EU prospects). A work email is personal data. B2B outreach usually relies on legitimate interest, people can object to direct marketing at any time, and you must say where you got their data by your first message (Article 14). Germany, among others, requires prior consent for marketing email even between businesses.
- TCPA (US calls and texts). In February 2024 the FCC ruled that AI-generated voices count as “artificial” under the TCPA, so AI calls need the called person’s prior express consent, and texts to mobile numbers count as calls. A lead who just filled in your form is a different case from a cold list (AI outbound calling has the details).
How to pick an AI SDR
Start by counting last month’s replies that never got a second follow-up and inbound leads answered after an hour. If those numbers are high, more outbound volume pours into the same leak. Then check the offer: an AI SDR scales what already works, and if a person can’t book meetings with your pitch, an agent won’t either. Before you sign, ask whose mailboxes it sends from, which CRM syncs on your plan and how long the contract runs. Our lead generation statistics help size what more top-of-funnel volume is worth.
- Already on Apollo, Outreach or Salesloft: turn on their AI before buying another seat.
- Net-new names at volume, with a proven offer: an autonomous agent. AiSDR Solo is the cheapest month-to-month test; 11x and Artisan suit enterprise budgets.
- Cold email volume across many domains on a budget: Instantly.
- Go with Carly if your pipeline leaks at the reply, the follow-up, the inbound lead that waits until morning or the booking: it runs all of that from your reps’ own mailboxes and business number and keeps your CRM current.
FAQ
What does an AI SDR do?
It finds and researches leads, writes and sends outreach, follows up, sorts and answers replies, books meetings and updates the CRM. Some also reach inbound leads by email, text or phone within minutes. Carly covers the replies, follow-ups, speed to lead and booking from your team’s own mailboxes.
Can an AI SDR replace a human SDR?
For follow-up, reply sorting, booking, CRM updates and fast inbound response, largely yes. Humans still win on live calls, tricky objections and choosing which accounts matter, so most teams run both.
How much does an AI SDR cost?
Self-serve agents start around $94 to $250 a month (Instantly, AiSDR), and 11x starts at $3,750 a month billed annually. A human SDR costs about $114,000 a year with benefits. Carly: Free Zapier-style workflows; AI agents from $35/month, with Carly for teams set up on a short call.
Is an AI SDR worth it?
Yes, when your offer already converts and the gap is coverage: too few first touches, slow replies or leads waiting hours. No, as a fix for a weak offer or a messy list. If replies and booking are the bottleneck, Carly is the cheaper fix.
What is the best AI SDR?
It depends which part of the job is failing. Our best AI SDR tools ranking compares them side by side, with Carly first for teams that lose deals after the first touch.
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