CallLoop posts per-minute voice rates, ships your agents live in under 24 hours, and welcomes SMBs on month-to-month terms. Synthflow's $0.12/min rate is meaningless once you blow past your minute cap and the overage charges land.
Synthflow publishes a base rate, then surprises you with overages the moment your campaign starts dialing. CallLoop ships one flat per-minute rate and never bills you for exceeding a cap.
| CallLoop Transparent rates | Synthflow AI Enterprise-only | |
|---|---|---|
| Per-minute voice rate | $0.13 / minno caps | $0.12 / min+ surprise overage |
| Monthly platform fee | $149 / moflat — all-in | Enterprise tier (SMBs gated) |
| Minutes included | Unlimited | Capped — overage applies |
| Setup & onboarding | Included — live in <24h | Enterprise onboarding |
| Contract terms | Month-to-month | Annual contractSMBs gated out |
| Price visibility | Public — on this page | Quote-only, enterprise-gated |
Run a 10,000-prospect outbound blast without watching a meter. CallLoop charges one flat per-minute rate — no monthly allotment, no overage line on your invoice.
$0.13 per minute of voice, $149 a month flat. The number you see on this page is the number on your invoice. No quote dance, no enterprise tier.
Built on Retell AI's carrier-grade voice stack — natural prosody, sub-second latency, ready for live transfer to your closers on complex discovery calls.
Either way you'll be on a real call with our team inside one business day. No SDR funnel, no enterprise gatekeeping, no "thanks for your interest."
30 minutes with a CallLoop engineer. We'll set up your first campaign live and show you the dashboard.
7-day trial, no card. We'll spin up a sandbox campaign on your real prospect list so you can compare voice quality and conversion side by side.
If your priority is no minute caps, transparent flat pricing, and SMB-first onboarding without an enterprise gate, CallLoop is the better fit. If you're a large enterprise that needs a fully bespoke deployment and you don't mind overage math on every campaign, Synthflow has more surface area — but you should expect capped minutes, surprise invoices, and an annual contract.
For sales teams that want to ship a campaign this week rather than this quarter, yes. CallLoop runs on Retell AI's carrier-grade voice, ships in under 24 hours, and publishes its per-minute rate ($0.13/min) and monthly fee ($149/mo) on the website — no quote, no enterprise gate, no SMB deferral. You can trial the actual product with your own prospect list before committing.
Synthflow publishes a base rate of $0.12/min, then bills overage once you exceed your plan's minute allotment — the real per-minute cost rises sharply during high-volume campaigns. CallLoop charges $0.13 per minute flat, no allotments, no caps, no overage line item on your invoice. The base rates look close on paper; the math diverges once a campaign is running.
Synthflow has pivoted upmarket. SMBs typically hit an enterprise sales motion, quote-only pricing, and annual contract requirements before they get access. CallLoop is built SMB-first: self-serve signup, month-to-month billing, live in under 24 hours, no annual commit. If you've been deferred by Synthflow, you'll be onboarded with us.
Synthflow's TTS has visible gaps on nuanced, multi-turn discovery calls — the kinds where prospects interrupt, change topics, or push back on pricing. CallLoop is built on Retell AI's carrier-grade voice stack with sub-second latency and natural prosody, so it holds up on the calls that matter. If you've heard demonstrably robotic responses on Synthflow on real prospect calls, that's the most common complaint teams cite when switching.
Yes. Your prospect lists, call scripts, and CRM hooks port over directly. Most teams run CallLoop in parallel for a week on a slice of their list, compare connect rates and demo bookings, then flip the rest of their volume over. There's no lock-in — CallLoop is month-to-month.