# 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.

- **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.

## 01. Time to first live 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.

- 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

**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.

## 02. Infrastructure and telephony

**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.

- 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

**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.

## 03. Version control and rollback

**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.

- 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

**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.

## 04. Call routing and transfers

**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.

- 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

**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.

## 05. Outbound at scale

**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.

- 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

**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.

## 06. Observability and QA

**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.

- 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

**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.

## Side by side

### Getting live

| | Assistable | Synthflow |
| --- | --- | --- |
| Self-serve signup | Yes | Free start advertised; pricing is sales-led |
| Time to first live call | Minutes, in one sitting | Their framing: idea to ROI in weeks |
| Enterprise contract floor | None, pay as you go | From $30,000 annually, per their pricing page |

### Platform

| | Assistable | Synthflow |
| --- | --- | --- |
| Version history and rollback | Yes | Yes |
| Branches that merge without re-pointing | Yes | Not documented |
| Outbound campaign engine | Windows, retries, A/B in product and API | Single-call API; campaigns not in current docs |
| QA | LLM judge on every call and chat | Test Center simulations, custom evals |

### Telephony

| | Assistable | Synthflow |
| --- | --- | --- |
| Buy numbers in-app | US local and toll-free | US, CA, AU at $1.50/mo |
| Bring your own SIP | TLS trunk auto-provisioned, every account | Enterprise plan required |
| Warm transfer with briefing | Yes | Yes |

### Pricing

| | Assistable | Synthflow |
| --- | --- | --- |
| Voice | $0.07/min all-in | From $0.08/min, per their blog |
| Messages | $0.02 each | 5 AI messages count as 1 usage minute |
| Platform fee | None | Sales-led; enterprise from $30,000/yr |
| Published rates | Yes | Blog only; billing docs say sales-led |

## 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.

## FAQ

**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.

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Source: https://www.assistable.ai/compare/synthflow