エンタープライズ専用になったSynthflowの代替サービス

代替サービス

1. 1

   Retell AI

   Retell AI

   編集部のおすすめ

   ★★★★★

   –

   A pay-as-you-go platform for building AI phone agents: you set up the agent, number and integrations, and pay per minute for each part of the stack.

   長所

   • No platform fee or contract: start with $10 in free credits and pay per second of use
   • A dashboard builder with templates, plus an Auto Receptionist setup that starts from your website
   • Books into Cal.com, Calendly and GoHighLevel and syncs calls to HubSpot, Salesforce and other CRMs
   • Keep your existing number over SIP, or buy one for $2 a month
   • Self-serve HIPAA BAA at no extra fee, plus SOC 2 Type II
   • Agents can speak 55 languages, depending on the voice and speech-recognition providers chosen

   短所

   • You build and tune the agent yourself, or pay an implementation team or partner to do it
   • The per-minute price stacks several fees (platform, model, voice, telephony, add-ons), so the real cost depends on choices a business owner may not understand
   • Silence and hold time are billed, and numbers, SMS and extra concurrency cost extra each month
   • Retell's own pages disagree on details such as the free allowance (60 minutes or $10 in credit)
   Retell AIを見る
2. 2

   Bland AI

   Bland

   ★★★★★

   $19.99/月

   An enterprise voice AI platform running on its own models, with one per-minute rate that covers the AI; self-serve plans start at $0.14 a minute.

   長所

   • One per-minute rate covers the AI, so there are no separate model, voice or transcription bills
   • Free Start plan with an inbound number and no card required
   • Runs on its own models, with on-premises or VPC deployment for enterprise customers
   • Speaks 40+ languages and can switch language mid-call
   • HIPAA with a BAA, SOC 2 Type II and GDPR for regulated businesses

   短所

   • Pitched at enterprises: the receptionist is yours to build, and hands-on help from Bland's engineers comes with Enterprise
   • Texting, warm transfers and the HIPAA BAA are Enterprise-only (texting also comes with the Agent Phone plan)
   • The Start plan caps you at 100 calls a day, and transferred minutes cost extra
   • Lower rates need the $299-a-month Build plan
   • Booking is documented only for Cal.com
   Bland AIを見る
3. 3

   Vapi

   Vapi

   ★★★★★

   $29/月

   A developer platform for voice AI agents: $0.05 a minute hosting plus the model, voice and transcription you pick, billed at cost.

   長所

   • Pick any model, voice and transcriber, billed at provider cost with no markup
   • A free US number and $5 in credits let you call a test agent within minutes
   • Dashboard templates for support and appointment scheduling, with Google Calendar and GoHighLevel booking tools
   • Blind and warm transfers, call recordings and an automatic summary after each call
   • Deep developer tooling: API, SDKs, CLI, config as code, simulations and monitoring

   短所

   • Built for developers: the receptionist logic, tools and providers are yours to configure
   • Costs stack from separate hosting, model, voice, transcription and telephony charges
   • The free number is US-only and inbound-only; outbound calls need a number from Twilio, Telnyx or another carrier
   • Texting needs your own Twilio account
   • HIPAA costs $2,000 a month extra
   Vapiを見る
4. 4

   Goodcall

   Goodcall

   ★★★★★

   $79/月

   An AI phone agent you build by chatting with an assistant, billed per unique caller instead of per minute, from $79 a month for 100 callers.

   長所

   • Billed per unique caller, not per minute: long calls and callbacks from the same number that month cost nothing extra
   • Published prices from $79 a month, month to month, with no setup fee and a local number included
   • Set up and change the agent by telling Gabi in plain words, with practice calls and approval before anything goes live
   • Transfers to up to three people in turn, retrying busy lines
   • Books into Google Calendar and sends leads to Google Sheets, HighLevel or 10,000+ apps via Zapier

   短所

   • Answers in English only
   • Local US numbers only: no toll-free, Canadian or international numbers yet
   • You can't port your number in yourself; you forward your existing line instead
   • Your Goodcall number can send texts but can't receive replies yet
   • HIPAA use with a BAA needs the $299 Scale plan or Enterprise
   Goodcallを見る
5. 5

   Upfirst

   Upfirst, Inc.

   ★★★★★

   $24.95/月

   An AI receptionist that answers calls and texts 24/7, books appointments and blocks spam, from $24.95 a month for 30 calls.

   長所

   • Cheap entry point: $24.95 a month for 30 calls, or $20 billed annually
   • Every feature on every plan, including booking, warm transfers, texting, recordings and 35+ languages
   • Spam, robocalls and calls under 15 seconds don't count toward your calls
   • 14-day trial (up to 100 calls) with no credit card, and month-to-month plans
   • Books into Google Calendar, Outlook, Calendly, Acuity, Square and Clio Manage, with Zapier and Make for the rest

   短所

   • Small plans fill up fast: 30 calls on Starter, then $1.50 per extra call
   • No refund if you prepay a year and cancel
   • BAAs for compliance are only on the custom Enterprise plan
   • No native mobile app; the web app can be saved to a phone's home screen
   • Each extra agent, for another location or business line, adds $9.95 a month
   Upfirstを見る
6. 6

   NextPhone

   Pure Labs Inc.

   ★★★★★

   $199/月

   An AI receptionist for law firms and service businesses with unlimited calls at a flat $199 a month, no per-minute fees and a 7-day free trial.

   長所

   • Flat $199 a month for unlimited inbound calls, with no per-minute charges, overage fees or setup fee
   • Self-serve signup with a 7-day free trial, month-to-month with no contract
   • Answers in 14 languages, switching when the caller does, with 30 voices to choose from
   • Books into Google, Outlook, Calendly, Acuity, Cal.com and OnceHub and texts the caller a confirmation
   • Says it never trains AI on your calls and has opted out of training with every AI provider it uses

   短所

   • Doesn't sign BAAs, and its terms forbid use with protected health information
   • Hasn't completed a SOC 2 audit of its own
   • CRM updates and Zapier, Make and API access start at the $299 Growth plan
   • 2-way texting and calling from your business number need the $599 Scale plan
   • No toll-free numbers
   NextPhoneを見る

機能

機能

	Synthflow	Retell AI	Bland AI	Vapi	Goodcall	Upfirst	NextPhone
最低料金	–	–	$19.99/月	$29/月	$79/月	$24.95/月	$199/月
課金方式	要見積もり	分単位	分単位	分単位	定額	通話単位	定額
無料プラン	✕なし	✕なし	✓あり	✕なし	✕なし	✕なし	✕なし
無料トライアル	✕なし	$10 in free credits	Free Start plan with 2 credits and an inbound number, no card required	$5 in free credits and a free US number for inbound calls	Free demo agent you can build and test; you pay once you add a phone number	14 days or 100 calls, whichever comes first, plus 25 texts; no credit card	7 days, cancel before it ends and you aren't charged
月単位で解約可	✕なし	✓あり	?記載なし	✓あり	✓あり	✓あり	✓あり
初期費用	?記載なし	なし	?記載なし	なし	なし	?記載なし	なし
電話番号付き	✕なし	✕なし	✓あり	✓あり	✓あり	✓あり	✓あり
今の番号を使える	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
通話を転送する	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
予約を受け付ける	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
発信者にSMSを送る	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
通話の要約	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
通話録音	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり
発信	✓あり	✓あり	✓あり	✓あり	?記載なし	?記載なし	?記載なし
迷惑電話フィルター	?記載なし	?記載なし	?記載なし	?記載なし	✓あり	✓あり	✓あり
人による対応	?記載なし	?記載なし	?記載なし	?記載なし	?記載なし	?記載なし	?記載なし
HIPAA	✓あり	✓あり	✓あり	✓あり	✓あり	✓あり	✕なし
対応言語	English, Spanish, French, German, Italian, Portuguese, Dutch, Catalan, Welsh, Greek, Swedish, Norwegian, Danish, Finnish, Polish, Romanian, Bulgarian, Czech, Slovak, Slovenian, Russian, Ukrainian, Turkish, Hebrew, Mandarin, Japanese, Korean, Malay, Hindi, Thai, Vietnamese, Indonesian	Afrikaans, Arabic, Armenian, Azerbaijani, Bosnian, Bulgarian, Cantonese, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Filipino, Finnish, French, Galician, German, Greek, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Italian, Japanese, Kannada, Kazakh, Korean, Latvian, Lithuanian, Macedonian, Malay, Marathi, Nepali, Norwegian, Persian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swahili, Swedish, Tamil, Thai, Turkish, Ukrainian, Urdu, Vietnamese, Welsh	English, Spanish, French, German, Italian, Portuguese, Dutch, Polish, Russian, Swedish, Danish, Finnish, Norwegian, Greek, Hungarian, Czech, Slovak, Romanian, Bulgarian, Ukrainian, Turkish, Hindi, Chinese (Mandarin), Japanese, Korean, Vietnamese, Indonesian, Malay	?記載なし	English	English, Spanish, French, Portuguese, Korean, Russian, Vietnamese	English, Spanish, French, German, Italian, Portuguese, Dutch, Russian, Arabic, Hindi, Mandarin, Japanese, Korean, Vietnamese
カレンダー	Cal.com, GoHighLevel	Cal.com, Calendly, GoHighLevel, Google Calendar, Squarespace Scheduling	Cal.com	Google Calendar, GoHighLevel	Google Calendar	Google Calendar, Outlook, Calendly, Acuity Scheduling, Square, Clio Manage	Google Calendar, Microsoft Outlook, Calendly, Acuity Scheduling, Cal.com, OnceHub
連携	Salesforce, HubSpot, Zoho, Zendesk, Freshworks, GoHighLevel, Twilio, Telnyx, Vonage, RingCentral, Five9, 8x8, Zoom	HubSpot, Salesforce, Microsoft Dynamics 365, Zoho CRM, GoHighLevel, Zendesk, Jobber, QuickBooks, Zapier, Make, n8n, Twilio, Vonage, Telnyx	Salesforce, HubSpot, Slack, Twilio	GoHighLevel, Twilio, Telnyx, Vonage	Google Sheets, HighLevel, Zapier	Zapier, Make, Clio, Custom API actions, MCP server	Clio Manage, Clio Grow, MyCase, Lawmatics, PracticePanther, HubSpot, Salesforce, GoHighLevel, Jobber, ServiceTitan, Housecall Pro, Zapier, Make, Slack, Webhooks
業種	Healthcare, Legal, Real estate, Home services	業種を問わず	Healthcare, Insurance, Financial services, Utilities, Government	業種を問わず	業種を問わず	Real estate, Law firms, Property management, Chiropractors, Contractors, Emergency restoration, Financial services, Franchises, HVAC, Insurance, Landscaping, Pest control, Plumbing, Restaurants, Salons, Towing, Veterinary	Legal, Financial services, Professional services, Real estate, Construction and trades, Home services, Beauty and personal care, Wellness and fitness, Food and dining, Automotive