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Comparison · Synthflow

Assistable vs Synthflow

Synthflow pairs a mature no-code builder with a sales-led enterprise motion and best-in-class white-label tooling for agencies. Assistable keeps the whole platform self-serve: sign up, get your first assistant and a local number, and go live in minutes at $0.07/min all-in.

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<500 ms latency·99.99% uptime·4.7/5 on Trustpilot

The bottom line

Assistable

Assistable is self-serve end to end. Onboarding creates your first assistant, grants $10 in usage credit, and sells you a US or Canadian local number in-app, and everything on this page, versioned publishing with one-click rollback, warm transfers with fallback hunting, the campaign dial engine, and QA on every call, runs on pay as you go at $0.07/min all-in with no platform fee.

Synthflow

Synthflow is a capable no-code voice platform that now sells enterprise-first: its pricing page lists enterprise contracts starting at $30,000 annually, its billing docs describe sales-led pricing scoped with their team, and SIP trunking requires the enterprise plan. Its second identity is a white-label platform for agencies, with subaccounts, custom domains, and Stripe rebilling.

The real comparison

Six places the platforms actually differ.

The same six questions on every comparison page. Here is how Assistable and Synthflow each answer them.

01 / 06

Time to first live call

From signup to an agent answering a real phone call.

Assistable

Sign up at platform.assistable.ai and onboarding creates your first assistant, grants $10 in usage credit, and sells you a real US or Canadian local number in-app. The first live call happens in minutes, in one sitting, with no sales call and no scoping exercise. Full production rollouts run 2-3 day deploys.

Synthflow

Synthflow's homepage still advertises a free start with pay as you go at launch, but the pricing page lists only enterprise contracts starting at $30,000 annually, and their billing docs state pricing is sales-led and scoped with their team. Their own framing for production is From Idea to ROI in Weeks, behind a four-step enterprise onboarding of scoping, security review, pricing agreement, and launch.

Assistable delivers

First assistant created automatically during onboarding·Free local phone number plus $10 in calling credit at signup·US and Canadian local numbers purchased in-app·2-3 day deploys for full production rollouts

02 / 06

Infrastructure and telephony

What you assemble before production, and who runs it.

Assistable

Numbers, SIP, recordings, and call control run on the platform's own carrier-grade voice stack on every account, and bring-your-own numbers get a TLS SIP trunk provisioned automatically, with SRTP as an explicit opt-in and clean rollback if provisioning fails. Compliance rails are built in: DNC scrubbing, honeypot detection, A2P 10DLC registration, and KYC review. Web chat, SMS, and voice share one channel gateway with identity resolution to a single contact record.

Synthflow

Synthflow sells US, Canadian, and Australian numbers in-app at $1.50 per month, positioned in their own docs for quick testing or simpler setups, with BYO Twilio for voice and SMS. SIP trunking and BYOC require an enterprise plan, where a wide contact-center matrix, Genesys, Five9, Talkdesk, 8x8, Zoom, and more, is a genuine strength.

Assistable delivers

US local and toll-free number search and purchase in-app·TLS SIP trunk auto-provisioned per imported number, no plan gate·DNC scrubbing, honeypot detection, and A2P 10DLC registration built in·<500 ms latency, 0.4s median answer, 99.99% uptime SLA

03 / 06

Version control and rollback

How changes ship, and how fast you can undo one.

Assistable

Synthflow ships real versioning, and Assistable goes deeper. Publishing writes an immutable numbered version to an append-only commit log with the author recorded, live traffic follows an explicit deploy pointer with a Live badge, rollback is one click, and branches stage bigger rewrites and merge into Main without changing the flow id, so numbers and endpoints never re-point. Publish is a role-based permission, and every publish and rollback is audit-logged.

Synthflow

Synthflow's version control is real and documented: every publish snapshots a version automatically, a timeline shows who changed what with a compare diff view, and you can revert to any previous version in one click. Their docs also state the edges plainly: direct API edits are not versioned, and actions are not yet included in version history. Branching is not documented.

Assistable delivers

Immutable numbered versions with author, in an append-only history·Explicit deploy pointer with one-click rollback·Branches merge into Main without changing the flow id·Publish and rollback are role-gated and audit-logged·Test drawer runs the draft against the production engine

04 / 06

Call routing and transfers

What happens when a caller needs a human.

Assistable

The transfer engine dials your team in order with fallback hunting, up to 6 dial attempts at a 25-second default ring timeout, screens every leg with answering-machine detection, and speaks a whisper briefing, static text or generated by the LLM from the live transcript, before bridging. Connected, voicemail, no-answer, and failed each route their own flow branch, and unanswered transfers can resume the AI instead of hanging up. Tag rules bind contacts to assistants per channel with priority and active hours, so time-of-day routing is a setting.

Synthflow

Synthflow's transfer stack is genuinely deep: warm transfer with whisper or AI-generated summary briefings, human detection so the briefing never reaches voicemail or an IVR, call screening where the recipient can question the AI before accepting, and retry-or-continue on a failed warm transfer. Phone books hold up to 50 destinations with per-number transfer conditions; the documented example is intent-based, and time-based conditions are not documented.

Assistable delivers

Ordered fallback hunting: up to 6 dial attempts, 25-second ring timeout each·Answering-machine detection screens every transfer leg·Whisper briefing generated by the LLM from the live transcript·Tag rules with priority and active hours for time-of-day routing·Per-minute sweep force-resolves stale holds

05 / 06

Outbound at scale

Dialing a list without burning it.

Assistable

Campaigns are in the product and the API: a dial engine converges every minute, calling windows are timezone-aware with day-of-week selection and overnight wrap, retries for no-answer, busy, and failed honor the window, and A/B splits across assistants converge on the configured percentages. Every dial passes DND, blacklist, and E.164 gates, and a wallet at zero pauses the campaign with a stated reason instead of burning the list.

Synthflow

Synthflow's public calls API is single-call only, with no batch, scheduling, or retry fields, and current docs point list outreach at Zapier, Make, or GoHighLevel loops with manual throttling to stay under rate caps. A batch campaigns capability appears in their support center and academy materials, but scheduling windows, retry cadence, and DNC handling are not documented in the current docs.

Assistable delivers

Minutely dial engine; claim-first updates prevent double dials·Timezone-aware windows with day-of-week selection and overnight wrap·A/B splits across assistants with per-assistant rollups·DND, blacklist, and E.164 checks on every dial·Enroll up to 25,000 contacts by filter, list, or CSV

06 / 06

Observability and QA

How you find out something went wrong.

Assistable

An LLM judge grades every finished call and chat against monitor rules you write in plain English, citing the decisive transcript moment with a confidence score. Repeat failures cluster into issues, the AI drafts a minimal prompt fix with a line diff, and proves it by replaying the failing conversation 3 times through the published flow; confidence is the measured pass rate, never self-reported. Per-rule health tracks fire rate, drift, silence, and human overturns.

Synthflow

Synthflow's QA tooling is a real strength: Test Center suites of AI-generated test cases with per-criterion pass and fail badges, custom evaluations that score live calls against business goals, an hourly analytics dashboard with sentiment and outcome trends, and API logs with request and retry history. Their docs note completed simulations may be billable per workspace configuration.

Assistable delivers

Every finished call and chat graded, not a sample·Verdicts cite the decisive transcript moment with confidence·Fixes proven by 3 replays before you apply them·Auto-apply off by default behind hard guardrails

At a glance

Side by side

Getting live

Self-serve signup
AssistableYes
SynthflowFree start advertised; pricing is sales-led
Time to first live call
AssistableMinutes, in one sitting
SynthflowTheir framing: idea to ROI in weeks
Enterprise contract floor
AssistableNone, pay as you go
SynthflowFrom $30,000 annually, per their pricing page

Platform

Version history and rollback
AssistableYes
SynthflowYes
Branches that merge without re-pointing
AssistableYes
SynthflowNot documented
Outbound campaign engine
AssistableWindows, retries, A/B in product and API
SynthflowSingle-call API; campaigns not in current docs
QA
AssistableLLM judge on every call and chat
SynthflowTest Center simulations, custom evals

Telephony

Buy numbers in-app
AssistableUS local and toll-free
SynthflowUS, CA, AU at $1.50/mo
Bring your own SIP
AssistableTLS trunk auto-provisioned, every account
SynthflowEnterprise plan required
Warm transfer with briefing
AssistableYes
SynthflowYes

Pricing

Voice
Assistable$0.07/min all-in
SynthflowFrom $0.08/min, per their blog
Messages
Assistable$0.02 each
Synthflow5 AI messages count as 1 usage minute
Platform fee
AssistableNone
SynthflowSales-led; enterprise from $30,000/yr
Published rates
AssistableYes
SynthflowBlog only; billing docs say sales-led

Synthflow capabilities and pricing reflect their publicly published information as of July 2026 and may change.

Why teams switch

Why teams choose Assistable.

01

Live the day you sign up

Onboarding creates your first assistant, grants $10 in calling credit, and sells you a real local number in-app. The first live call happens in minutes, and full production rollouts run 2-3 day deploys.

02

Version control for agents

Immutable numbered versions in an append-only history, an explicit deploy pointer with one-click rollback, and branches that merge without changing the flow id. Live traffic never executes an open draft.

03

Telephony that behaves like a phone system

Ordered team hunting with answering-machine detection, whisper briefings generated from the live transcript, tag rules with active hours, and DND, blacklist, and wallet gates on every outbound dial.

Under the hood

The infrastructure
most platforms rent.

We operate dedicated network, telephony, and compliance rails, and let you choose the models on top. That is what keeps conversations fast, clear, and safe at scale.

  • Edge

    Co-located edge PoPs and GPUs power low-latency voice AI globally.

  • Telephony

    A full telephony stack built in: native calling and texting without wiring a carrier.

  • Network

    Audio runs on a private global network, bypassing the public internet for call quality.

  • Compliance

    A programmatic compliance layer: DNC and honeypot detection, 10DLC and KYC, attribution reporting.

  • Models

    LLM, TTS, and STT à la carte, self-hosted or from major providers. Enterprises can bring their own keys.

  • Languages

    100+ languages and dialects, with real-time multilingual transcription and translation.

  • Coverage

    Calling and texting in 105+ countries.

Questions

Assistable vs Synthflow, answered.

What is the difference between Assistable and Synthflow?
Synthflow pairs a mature no-code builder with a sales-led enterprise motion and best-in-class white-label tooling for agencies. Assistable keeps the whole platform self-serve: sign up, get your first assistant and a local number, and go live in minutes at $0.07/min all-in.
Is Assistable or Synthflow more cost effective?
Assistable is usage-based at $0.07 per minute for voice, all-in, and $0.02 per message, with no platform fee, no seat fees, and free pay-as-you-go signup. Synthflow's published pricing model is sales-led; $30k+ enterprise. Assistable bundles telephony, model, and voice into one per-minute rate, so there are no per-component add-ons to reconcile.
When should I choose Synthflow over Assistable?
Synthflow is the right call for two buyers. Agencies reselling voice agents under their own brand get the most complete white-label stack in the category: subaccounts with granular permissions, custom domains and branding, and Stripe rebilling where the agency sets its own plan prices, included minutes, and overage rates. And enterprises embedding AI into an existing contact center get a wide SIP matrix across Genesys, Five9, Talkdesk, 8x8, Dialpad, and Zoom, a vendor-led deployment framework, serious QA tooling in Test Center, and their claimed scale of 65M+ monthly voice calls across 30+ countries. If either profile fits, Synthflow deserves the shortlist.
How fast can I get a live AI agent with Assistable?
Signup is self-serve. Onboarding creates your first assistant, grants $10 in usage credit, and lets you buy a US or Canadian local number in-app, so the first live call happens in minutes without a sales call. Full production rollouts run 2-3 days.

Fair is fair

When Synthflow is the right call

Synthflow is the right call for two buyers. Agencies reselling voice agents under their own brand get the most complete white-label stack in the category: subaccounts with granular permissions, custom domains and branding, and Stripe rebilling where the agency sets its own plan prices, included minutes, and overage rates. And enterprises embedding AI into an existing contact center get a wide SIP matrix across Genesys, Five9, Talkdesk, 8x8, Dialpad, and Zoom, a vendor-led deployment framework, serious QA tooling in Test Center, and their claimed scale of 65M+ monthly voice calls across 30+ countries. If either profile fits, Synthflow deserves the shortlist.

Results

Take their word for it.

Real operators, verified reviews, and one 18-month evaluation that ended with 25,000 flawless calls.

Platform lifetime

m+managed conversations

Across voice, SMS, WhatsApp, and chat.

Reliability

% uptime

Production uptime, backed by SLA.

Speed

s median answer

From first ring to answered, on every channel.

Verified customer · 18-month evaluation

25,000 calls delivered flawlessly.

“After 18 months testing voice AI platforms including Bland.ai and Synthflow.ai… Assistable delivered flawlessly on over 25,000 calls in recent weeks. It checks all the boxes with built-in features that more mature platforms haven’t integrated yet.”

Maurice M.Verified customer

Backed by a Shark

“Assistable AI is redefining business efficiency.”

KHKevin HarringtonKevin HarringtonOriginal Shark, Shark Tank
Watch →
Trustpilot4.7/5 · 35 verified reviewsHighLevel4.5/5 · 126,000+ marketplace downloads
  • “I've tested a lot of AI and automation tools, and most fall apart once you try to scale. Assistable is the real deal.”
    Jamie WVerified Trustpilot review
  • “I have been using Assistable for about 10 months, and it has changed my business completely. The voice AI quality is unmatched.”
    Travis HolzemVerified Trustpilot review
  • “The conversational quality and flexibility are amazing. Top notch tech and service from the entire team.”
    Eric KnellerVerified Trustpilot review
  • “They make it so easy to get started with voice AI. The onboarding was smooth and the results were immediate.”
    Pam VinjeVerified Trustpilot review
  • “There is no better conversational AI voice bot. There are a ton of players in the market and Assistable leads.”
    Lowe SmithVerified Trustpilot review
  • “Assistable has been a game changer for my business and is way easier to use than any alternative I've tried.”
    Greg PfefferVerified Trustpilot review
  • “Assistable AI was the best decision we have made for our company in a long time. Excellent product and team.”
    Get Amplified MarketingVerified Trustpilot review
  • “Been using Assistable for several months and it has completely changed how our team handles inbound inquiries.”
    ATVerified Trustpilot review
  • “There is no better conversational AI voice bot. There are a ton of players in the market and Assistable leads.”
    Lowe SmithVerified Trustpilot review
  • “Assistable has been a game changer for my business and is way easier to use than any alternative I've tried.”
    Greg PfefferVerified Trustpilot review
  • “Assistable AI was the best decision we have made for our company in a long time. Excellent product and team.”
    Get Amplified MarketingVerified Trustpilot review
  • “Been using Assistable for several months and it has completely changed how our team handles inbound inquiries.”
    ATVerified Trustpilot review
  • “I've tested a lot of AI and automation tools, and most fall apart once you try to scale. Assistable is the real deal.”
    Jamie WVerified Trustpilot review
  • “I have been using Assistable for about 10 months, and it has changed my business completely. The voice AI quality is unmatched.”
    Travis HolzemVerified Trustpilot review
  • “The conversational quality and flexibility are amazing. Top notch tech and service from the entire team.”
    Eric KnellerVerified Trustpilot review
  • “They make it so easy to get started with voice AI. The onboarding was smooth and the results were immediate.”
    Pam VinjeVerified Trustpilot review

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