Synthflow AI
PaidNo-code voice AI agent platform for automating inbound and outbound phone calls
What is Synthflow AI?
Synthflow AI is a no-code platform for building and deploying AI-powered voice agents that handle real phone calls -- both inbound and outbound. Founded in 2023, Synthflow has carved out a niche in the voice AI agent space by making it possible for non-technical users to create phone agents that can book appointments, qualify leads, handle customer support, send follow-up messages, and transfer calls to human agents when needed. The platform uses leading TTS providers (ElevenLabs, PlayHT) for natural-sounding voices and supports real-time calendar booking during live calls. Synthflow targets three main audiences: SMBs wanting to automate phone handling, agencies reselling white-labeled voice agents to clients, and enterprises needing scalable phone automation. Key integrations include HubSpot, Salesforce, GoHighLevel, Zapier, and Make. Unlike general-purpose automation tools like n8n or Lindy AI, Synthflow is laser-focused on voice -- it does not automate email, chat, or workflow triggers outside of phone calls. This specialization is both its strength (the voice UX is polished) and its limitation (you will need other tools for non-voice automation). Pricing starts at $29/month for 50 minutes on the Starter plan, scaling up to $1,250/month for 6,000 minutes on Agency. There is no free plan or trial, which is a notable barrier to entry compared to competitors.
⚡ Quick Verdict
Agencies and SMBs wanting no-code AI phone agents for appointment booking, lead qualification, and support
Teams needing general workflow automation, email agents, or low-cost voice AI at scale
Starter $29/mo (50 min) · Pro $375/mo · Growth $750/mo · Agency $1,250/mo
No free plan or free trial
Polished no-code builder for voice agents with real-time booking and agency white-labeling
Voice-only -- no email, chat, or workflow automation outside of phone calls
Bottom line: Synthflow AI scores 4.2/5 -- the best no-code voice AI builder for agencies and SMBs who want phone agents without writing code. The lack of a free tier and voice-only focus keep it from scoring higher.
Pricing
No free plan or trial. All plans are paid from day one.
Starter -- $29/month: 50 included minutes, 5 concurrent calls, unlimited AI assistants, API integrations, real-time booking, human call transfer. Phone number costs $1.50/month extra.
Pro -- $375/month (annual) / $450/month (monthly): 2,000 included minutes, full CRM integrations (HubSpot, Salesforce, GoHighLevel), all Starter features plus advanced analytics and priority support.
Growth -- $750/month (annual) / $900/month (monthly): 4,000 included minutes, everything in Pro with higher concurrency limits and volume pricing.
Agency -- $1,250/month (annual) / $1,400/month (monthly): 6,000 included minutes, white-labeling, sub-accounts, rebilling to clients, dedicated account manager.
Add-ons: Extra concurrency slots cost $20/slot/month (up to 50 additional). Overage minutes billed per-minute. Custom Enterprise pricing available above 6,000 minutes.
Key Features
- No-code voice AI agent builder with visual flow editor
- Inbound and outbound phone call automation
- Real-time appointment booking during live calls (Google Calendar, Calendly)
- Human call transfer with context handoff
- Native CRM integrations: HubSpot, Salesforce, GoHighLevel, Zoho
- White-label and sub-accounts for agencies
- Rebilling system -- agencies set their own per-minute rates for clients
- Multi-language support with ElevenLabs and PlayHT voice synthesis
- Voicemail detection and after-hours call handling
- Zapier and Make integrations for workflow triggers
Pros & Cons
Pros
- Best no-code UX for building voice AI agents -- no engineering needed
- Real-time booking during calls is a standout feature for appointment-heavy businesses
- Strong agency features: white-labeling, sub-accounts, rebilling
- GoHighLevel integration makes it ideal for marketing agencies
- Natural-sounding voices via ElevenLabs with sub-second latency
Cons
- No free plan or trial -- $29/month minimum just to test
- Voice-only platform -- no email, chat, or general workflow automation
- Starter plan's 50 minutes is barely enough for real usage
- Per-minute costs add up quickly for high-volume deployments
- Pro plan jumps from $29 to $375 -- large gap with no mid-tier option
FAQ
How much does Synthflow AI cost?
Synthflow has four tiers on annual billing. Starter at $29/month includes 50 minutes and 5 concurrent calls. Pro at $375/month includes 2,000 minutes with full CRM integrations. Growth at $750/month provides 4,000 minutes. Agency at $1,250/month covers 6,000 minutes. Monthly billing is slightly higher (Pro $450, Growth $900, Agency $1,400). All plans include unlimited AI assistants and API access. Additional minutes and concurrency slots are available as add-ons.
Does Synthflow AI have a free plan?
No. Synthflow does not offer a free plan or a free trial. The cheapest entry point is the Starter plan at $29/month with 50 included minutes. This is a significant barrier compared to competitors like n8n and Make, which offer free tiers. If you need to test voice AI before committing, platforms like Bland AI or Vapi offer more accessible entry points.
What is Synthflow AI used for?
Synthflow is a no-code platform for building AI-powered voice agents that handle phone calls. Common use cases include appointment scheduling, lead qualification, customer support calls, outbound sales follow-ups, payment reminders, and after-hours call handling. The AI agents can book meetings in real-time, transfer calls to humans, and integrate with CRMs like HubSpot and Salesforce.
How does Synthflow compare to Bland AI?
Both are voice AI platforms, but they target different users. Synthflow focuses on no-code simplicity with a visual builder and pre-built templates -- ideal for agencies and SMBs. Bland AI is more developer-oriented with API-first pricing and deeper customization. Synthflow's per-minute pricing is higher, but the no-code builder saves engineering time. Bland AI wins on raw cost per minute for high-volume deployments.
Can Synthflow integrate with my CRM?
Yes. Synthflow integrates natively with HubSpot, Salesforce, GoHighLevel, and Zoho CRM. It also connects to Zapier, Make, and webhook endpoints for custom integrations. The Pro plan and above include full CRM access. On Starter, integrations are limited to API and basic webhook connections.
Is Synthflow good for agencies?
Yes -- Synthflow is one of the few voice AI platforms with explicit agency support. The Agency plan ($1,250/month) includes white-labeling, sub-accounts, and 6,000 minutes. Agencies can resell Synthflow-powered voice agents to clients with custom branding. The rebilling feature lets agencies set their own per-minute rates. GoHighLevel integration is a big draw for marketing agencies already on that stack.
What voice quality does Synthflow use?
Synthflow uses leading text-to-speech providers including ElevenLabs and PlayHT for natural-sounding voices. The platform supports multiple languages and voice cloning on higher-tier plans. Latency is typically under 1 second for responses, which feels natural in conversation. Voice quality is competitive with Bland AI and Retell AI, though dedicated TTS platforms like ElevenLabs still sound slightly more natural in side-by-side comparisons.
📋 Good to know
Sign up at synthflow.ai, choose a plan, build your first voice agent with the visual flow editor, connect a phone number ($1.50/month), and start receiving calls within 30 minutes.
GDPR compliant, SOC 2 in progress. Call recordings stored encrypted. Enterprise customers can negotiate data residency requirements.
Starter's 50 minutes runs out fast -- most real deployments need Pro ($375/month) within the first month. Agency is worth it only if you are reselling to 3+ clients.
Low for basic call flows. The visual builder abstracts most complexity. Advanced features like conditional branching and CRM field mapping take a few hours to learn.