{ "name": "Voice Agent Index benchmark vendor proof pages", "updatedAt": "2026-06-28", "vendors": [ { "vendor": "Retell AI", "slug": "retell-ai", "category": "Developer voice agent platform", "profileUrl": "https://voiceagentindex.com/tools/retell-ai/", "benchmarkUrl": "https://voiceagentindex.com/benchmarks/vendors/retell-ai/", "jsonUrl": "https://voiceagentindex.com/benchmarks/vendors/retell-ai.json", "evidenceState": "Profiled, with public claims to verify and a standardized evidence packet still needed before scored benchmark results.", "bestUse": "Custom voice-agent builds, agency deployments, scheduling, lead qualification, and workflows that need developer control.", "publicSignals": [ "Local profile positions Retell AI as a low-latency voice agent platform for developers, agencies, and teams building custom receptionists.", "The profile highlights scheduling, inbound, outbound, SIP, Cal.com, and Google Calendar as evaluation surfaces buyers should verify.", "The strongest buyer test is a production-equivalent call with a calendar or CRM action, caller correction, and human transfer." ], "missingEvidence": [ "Timestamped call recordings showing first greeting, first useful response, interruptions, and tool waits.", "Transfer artifacts that show destination, transfer trigger, transcript context, and whether the human received the reason.", "Calendar or CRM action logs tied to the same call transcript and final summary.", "Failed-tool and noisy-audio examples, not only polished successful demo calls." ], "proofPacket": [ "Three inbound scheduling recordings with transcripts and timing checkpoints.", "One failed calendar-slot call showing safe recovery and no invented booking.", "One human handoff call with transfer event, destination, and summary payload.", "Tool or webhook logs mapped to the call ID and post-call analysis fields." ] }, { "vendor": "Vapi", "slug": "vapi", "category": "Developer voice agent API", "profileUrl": "https://voiceagentindex.com/tools/vapi/", "benchmarkUrl": "https://voiceagentindex.com/benchmarks/vendors/vapi/", "jsonUrl": "https://voiceagentindex.com/benchmarks/vendors/vapi.json", "evidenceState": "Profiled, with implementation-dependent outcomes and standardized proof needed before scored benchmark results.", "bestUse": "Developer-owned phone agents, product-embedded voice workflows, custom tools, webhooks, and reusable agency builds.", "publicSignals": [ "Local profile positions Vapi for developers, product teams, and custom agent builders.", "The profile highlights telephony, custom tools, webhooks, assistant configuration, and call analysis as evaluation surfaces.", "Results depend heavily on the buyer's architecture, model choices, tool design, and monitoring process." ], "missingEvidence": [ "Reference assistant configuration for the tested workflow, including tools, model choices, and phone route.", "Call logs that show tool timeouts, retries, failures, and downstream webhooks.", "Transfer configuration and proof that the human receives useful context.", "Cost trace for representative calls across model, voice, telephony, and platform layers." ], "proofPacket": [ "One simple call and one tool-heavy call using the same published benchmark script.", "Assistant, tool, and phone-number configuration screenshots or exports.", "Structured call analysis, webhook payloads, and failed-tool logs for the same call IDs.", "Human transfer recording and summary packet." ] }, { "vendor": "Bland AI", "slug": "bland-ai", "category": "Enterprise voice AI", "profileUrl": "https://voiceagentindex.com/tools/bland-ai/", "benchmarkUrl": "https://voiceagentindex.com/benchmarks/vendors/bland-ai/", "jsonUrl": "https://voiceagentindex.com/benchmarks/vendors/bland-ai.json", "evidenceState": "Profiled, with public evidence to check and a standardized evidence packet still needed before scored benchmark results.", "bestUse": "Enterprise voice workflows, structured inbound or outbound call paths, lead qualification, and operations automation.", "publicSignals": [ "Local profile positions Bland AI for enterprise teams, complex call flows, and operations teams.", "The profile highlights pathways, inbound and outbound workflows, calendars, CRMs, custom tools, logs, transfers, and analytics.", "Outbound workflows require separate consent, suppression, opt-out, retry, and disclosure review before volume." ], "missingEvidence": [ "Pathway or workflow map tied to each benchmark call.", "Failed-call examples showing voicemail, no-answer, opt-out, correction, and transfer behavior.", "CRM, webhook, or calendar logs for completed and failed actions.", "Policy proof for escalation, consent, suppression, retry, and recording rules where relevant." ], "proofPacket": [ "One pathway export or workflow screenshot for the tested benchmark scenario.", "Recordings and transcripts for successful and failed calls.", "Branch usage, webhook logs, transfer packet, and analytics view for the same call IDs.", "Outbound governance packet if the benchmark includes outbound calling." ] }, { "vendor": "Synthflow", "slug": "synthflow", "category": "No-code enterprise voice AI", "profileUrl": "https://voiceagentindex.com/tools/synthflow/", "benchmarkUrl": "https://voiceagentindex.com/benchmarks/vendors/synthflow/", "jsonUrl": "https://voiceagentindex.com/benchmarks/vendors/synthflow.json", "evidenceState": "Profiled, with public evidence to check and standardized workflow proof needed before scored benchmark results.", "bestUse": "No-code and enterprise voice automation, BPO workflows, support triage, scheduling, qualification, and routing.", "publicSignals": [ "Local profile positions Synthflow for enterprise teams, BPOs, agencies, and no-code voice automation.", "The profile highlights HubSpot, Zapier, enterprise telephony, workflow building, analytics, transfer behavior, and QA review.", "The strongest test is whether an operations user can review call logs and adjust one workflow behavior without developer delay." ], "missingEvidence": [ "Workflow builder evidence for the exact benchmark scenario.", "Analytics, review, and QA screenshots connected to benchmark calls.", "Transfer setup showing context passed to staff and what requires vendor support.", "Role, approval, retention, security, HIPAA, and GDPR documentation for regulated deployments." ], "proofPacket": [ "No-code workflow screenshots or exports for the tested call path.", "Recordings, transcripts, analytics views, and failed-intent logs.", "Calendar, CRM, ticketing, or transfer evidence tied to the same call IDs.", "Change-ownership proof showing what the buyer can edit without vendor or developer help." ] }, { "vendor": "Goodcall", "slug": "goodcall", "category": "AI receptionist", "profileUrl": "https://voiceagentindex.com/tools/goodcall/", "benchmarkUrl": "https://voiceagentindex.com/benchmarks/vendors/goodcall/", "jsonUrl": "https://voiceagentindex.com/benchmarks/vendors/goodcall.json", "evidenceState": "Profiled, with booking scenario ready and policy, handoff, latency, and noisy-caller proof still needed before scored benchmark results.", "bestUse": "Small business call answering, missed-call recovery, lead capture, appointment requests, after-hours coverage, and simple routing.", "publicSignals": [ "Local profile positions Goodcall as an AI phone agent and virtual receptionist for small businesses and local operators.", "The profile highlights no-code setup, inbound calls, lead capture, scheduling, Google Business Profile, Zapier, and calendars.", "The strongest SMB test is whether staff can understand summaries, update call behavior, and follow up quickly." ], "missingEvidence": [ "Local-service call recordings with incomplete information, caller corrections, and questions the agent should not answer.", "Staff notification, lead summary, SMS, callback, or booking artifacts tied to the same call.", "Policy proof for healthcare, legal, financial, urgent, or high-value calls.", "Noisy-caller and after-hours examples showing safe capture rather than over-answering." ], "proofPacket": [ "Three inbound SMB call recordings covering quote request, appointment request, and incomplete contact details.", "Dashboard or notification evidence showing what staff see after the call.", "Booking, SMS, callback, or Zapier artifact for the same test call.", "Policy and escalation documentation for calls the agent should route instead of answer." ] } ] }