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Synthflow alternatives

8 tools we tested head to head against Synthflow, ranked — and what each one actually does differently.

last reviewed 29 jul 2026 · from our best 9 ai voice agent platforms ·list curated by Onur Ozcanxin

first — what you'd be leaving

Synthflow ranks #9 of 9 in our ai voice agent platforms testing. free to build, undisclosed to run, and $30,000 a year to buy properly..

56/100

a coherent enterprise offering with the least public pricing of the nine — you can build an agent for free and cannot find out what running it costs.

why people look for an alternative
  • −no published per-minute rate for any tier
  • −enterprise floor of $30,000 a year
  • −data fine-tuning scope not clarified
  • −no self-hosting or on-premise option

stay with Synthflow if free to build and test agents from templates is the thing you care about most — nothing below beats it on that.

the short version
best alternativeRetell AIteams who want one number they can plan against rather than five they have to assemble.89/100best free optionPipecatteams who want to swap any component without changing platform, and pay nobody for the privilege.84/100
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  1. 1

    Retell AI

    #1 in ai voice agent platforms · the only vendor whose headline band already includes telephony, stt, tts and the llm — with the sub-rates printed underneath.

    89/100

    verdictthe most transparent pricing in the category and close to a real all-in figure — provided you resist the add-on menu that can double it.

    Retell AI vs Synthflow
     SynthflowRetell AI
    priceunpublished$0.07/min
    free tieryesyes
    headline ratenot published$0.07-0.31/min
    what it coversunconfirmedinfra, stt, tts, llm, us telephony
    realistic all-innot derivable$0.08-0.31 plus add-ons
    self-hostnot offeredenterprise on-prem
    concurrencycustom, enterprise only20 included

    switch forteams who want one number they can plan against rather than five they have to assemble.

    pros
    • +publishes per-component sub-rates, unique here
    • +band already includes telephony, stt, tts and llm
    • +20 concurrent calls included as standard
    • +genuine on-premise enterprise deployment
    cons
    • −add-ons can roughly double the effective per-minute cost
    • −ai quality assurance alone is $0.10/min after 100 minutes
    • −premium llm choices push the band to $0.31
    • −training on customer calls not addressed
    visit Retell AI →full Retell AI review →
  2. 2

    LiveKit Agents

    #2 in ai voice agent platforms · apache 2.0 top to bottom — self-host it and the platform fee simply stops existing.

    87/100

    verdictthe best licence in the category and the most honest component pricing — you just have to do the addition yourself.

    LiveKit Agents vs Synthflow
     SynthflowLiveKit Agents
    priceunpublished$0.01/min
    free tieryesyes
    headline ratenot published$0.01/min session
    what it coversunconfirmedorchestration only
    realistic all-innot derivable~$0.095/min mid-tier
    self-hostnot offeredyes, apache 2.0
    concurrencycustom, enterprise only5 free, up to 600

    switch forengineering teams who want to own the deployment and pay providers directly.

    pros
    • +apache 2.0 framework and media server, verified in the repo
    • +self-hosting eliminates the platform fee entirely
    • +publishes rate ranges for every billed component
    • +1,000 free agent session minutes a month
    cons
    • −no blended all-in figure anywhere
    • −cloud pricing means summing five metered lines
    • −free tier caps at five concurrent sessions
    • −no published latency figure
    visit LiveKit Agents →full LiveKit Agents review →
  3. 3

    Pipecat

    #3 in ai voice agent platforms · bsd-licensed, provider-agnostic, and free if you run it yourself — the framework the others are competing with.

    84/100

    verdictthe most flexible option here and the one that requires the most assembly — there is no bundled price anywhere in the stack because there is no bundle.

    Pipecat vs Synthflow
     SynthflowPipecat
    priceunpublishedfree self-hosted
    free tieryesno
    headline ratenot published$0.01-0.03/min compute
    what it coversunconfirmedcompute only
    realistic all-innot derivable$0.07-0.18/min hosted
    self-hostnot offeredyes, bsd 2-clause
    concurrencycustom, enterprise onlyunlimited (pay-per-use)

    switch forteams who want to swap any component without changing platform, and pay nobody for the privilege.

    pros
    • +bsd 2-clause, fully open and self-hostable
    • +cheapest hosted compute at $0.01-0.03/min
    • +unlimited concurrency on pay-per-use
    • +free 1:1 voice transport and 10,000 minutes of noise removal
    cons
    • −no bundled pricing anywhere in the stack
    • −you must supply and pay every ai provider yourself
    • −no free-minute allowance on cloud compute
    • −no published latency figure
    visit Pipecat →full Pipecat review →
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  4. 4

    Bland AI

    #4 in ai voice agent platforms · bundles the llm, stt and tts with no token charges — the simplest bill here, with telephony left outside it.

    81/100

    verdictgenuinely bundled where it matters and honest about the one thing it isn't — plus the highest published concurrency ceiling in the category.

    Bland AI vs Synthflow
     SynthflowBland AI
    priceunpublished$0.11/min
    free tieryesyes
    headline ratenot published$0.11-0.14/min
    what it coversunconfirmedllm, stt, tts
    realistic all-innot derivable$0.12-0.17/min
    self-hostnot offeredenterprise on-prem
    concurrencycustom, enterprise only10 to 100

    switch forteams that want a predictable talk-time rate and already have telephony sorted.

    pros
    • +llm, stt and tts genuinely bundled with no token charges
    • +highest published concurrency at 100 on scale
    • +on-premise with regional data residency for enterprise
    • +bring your own twilio removes transfer fees
    cons
    • −telephony sits outside the bundled rate
    • −transfer time billed at $0.03-0.05/min unless byot
    • −latency comparison is bland's own
    • −training on customer calls not addressed
    visit Bland AI →full Bland AI review →
  5. 5

    Vapi

    #5 in ai voice agent platforms · five cents a minute for vapi, and everything that makes a phone call work costs extra.

    77/100

    verdictthe cheapest markup in the category, attached to a pricing page that never shows you what a complete call costs.

    Vapi vs Synthflow
     SynthflowVapi
    priceunpublished$0.05/min
    free tieryesyes
    headline ratenot published$0.05/min
    what it coversunconfirmedorchestration only
    realistic all-innot derivable$0.15-0.30/min (our estimate)
    self-hostnot offerednot offered
    concurrencycustom, enterprise only10, +$10/line

    switch forteams with existing provider contracts who want orchestration and nothing else.

    pros
    • +lowest orchestration markup at $0.05/min
    • +bring your own keys zeroes the pass-through entirely
    • +clear split between vapi's fee and provider cost
    • +10 concurrent lines on the entry plan
    cons
    • −headline covers none of stt, llm, tts or telephony
    • −no worked example of a complete call anywhere
    • −trust and security page returns 404
    • −training on customer calls unverifiable
    visit Vapi →full Vapi review →
  6. 6

    Telnyx Voice AI

    #6 in ai voice agent platforms · calls its rate 'all-in' on a page that lists telephony and llm tokens as separate charges.

    74/100

    verdictgenuinely fast infrastructure and a genuinely misleading label — 'all-in' excludes the phone call and the model.

    Telnyx Voice AI vs Synthflow
     SynthflowTelnyx Voice AI
    priceunpublished$0.05/min
    free tieryesno
    headline ratenot published$0.05/min
    what it coversunconfirmedstt, tts, orchestration
    realistic all-innot derivable$0.07-0.10/min
    self-hostnot offerednot offered
    concurrencycustom, enterprise onlynot published

    switch forteams who want telephony and inference from one vendor on co-located infrastructure.

    pros
    • +sub-200ms latency claim from co-located infrastructure
    • +stt, tts and orchestration genuinely bundled
    • +broad included voice roster before premium tiers
    • +single vendor for telephony and inference
    cons
    • −'all-in' excludes telephony and llm tokens
    • −premium voices billed per character on top
    • −concurrency limits not published
    • −no free tier figure disclosed
    visit Telnyx Voice AI →full Telnyx Voice AI review →
  7. 7

    ElevenLabs Agents

    #7 in ai voice agent platforms · the best voices in the business, sold without an agent price anywhere on the site.

    66/100

    verdictthe voice quality is the reason anyone considers it, and it is the only platform here whose own pages never state what a minute of conversation costs.

    ElevenLabs Agents vs Synthflow
     SynthflowElevenLabs Agents
    priceunpublishedunverified
    free tieryesyes
    headline ratenot publishednot published
    what it coversunconfirmedshared credit pool
    realistic all-innot derivablenot derivable
    self-hostnot offerednot offered
    concurrencycustom, enterprise onlynot published

    switch forteams already on elevenlabs credits who value voice quality above cost predictability.

    pros
    • +the strongest voice quality in the category
    • +zero-retention mode available for stricter data control
    • +free plan with 10,000 shared credits a month
    • +one credit pool across tts, stt and agents
    cons
    • −no agent per-minute rate published anywhere
    • −no credits-per-agent-minute conversion given
    • −retention is the default; opt-out is manual
    • −concurrency not published — seats are not sessions
    visit ElevenLabs Agents →full ElevenLabs Agents review →
  8. 8

    Millis AI

    #8 in ai voice agent platforms · the lowest teaser rate in the category, on a pricing page that returns 404.

    60/100

    verdicta live, working product whose price cannot be verified because the page that would state it does not load.

    Millis AI vs Synthflow
     SynthflowMillis AI
    priceunpublished$0.02/min
    free tieryesno
    headline ratenot published$0.02/min teaser
    what it coversunconfirmedunconfirmed
    realistic all-innot derivablenot derivable
    self-hostnot offerednot offered
    concurrencycustom, enterprise onlynot published

    switch fornobody yet — check back when the pricing page is restored.

    pros
    • +lowest headline rate at $0.02/min
    • +choose your own llm and voice provider
    • +supports custom voice clones
    • +confirmed active with a maintained changelog
    cons
    • −pricing page returns 404 on both domains
    • −what the $0.02 covers is entirely unconfirmed
    • −no free tier, concurrency or latency figures published
    • −data handling not addressed anywhere reachable
    visit Millis AI →full Millis AI review →

how these were compared

every tool on this page went through the same test as Synthflow — same tasks, same order, scored the same way. the comparison tables are the figures from that testing, not vendor spec sheets.

the ai voice agent platforms test in full →
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