Head-to-head
Respond.io vs Trengo: Which Should You Pick in 2026?
A sales-automation powerhouse against a European customer-service suite. Compared honestly on pricing, tooling and fit, plus the lane both of them cannot serve.
Pricing and features verified against each vendor's site on August 1, 2026
Respond.io and Trengo both put WhatsApp inside an omnichannel team inbox, but they optimize for different jobs. Respond.io leans toward sales and automation: AI agents, workflow logic and deep reporting, billed by seats and Monthly Active Contacts from $99/mo. Trengo, from the Netherlands, is a customer-service platform first: ticketing-style workflows, SLA features, CSAT measurement and voice support, billed as plans with generous seat counts and yearly conversation allowances from EUR 299/mo.
Here is the dimension-by-dimension comparison with published 2026 pricing, followed by the structural limits both share as Business API platforms, and what to do if those limits are your real problem.
Respond.io vs Trengo vs Spun at a glance
| Feature | Respond.io | Trengo | Spun |
|---|---|---|---|
| Pricing model | Plan + contacts + users | Plan + conversation caps | Flat, whole team |
| Entry price (paid) | $99/mo | EUR 299/mo (annual) | $50/mo flat |
| Unlimited team members | |||
| Needs Business API approval | |||
| Per-message Meta fees | |||
| Works with your existing number | |||
| WhatsApp groups | |||
| Message templates required | |||
| AI compose / summary / ask-a-chat | AI agents | AI agent | |
| Voice note transcription | |||
| Speech-to-speech translation | |||
| Per-customer team scoping | Advanced roles | Teams | |
| Ticketing / SLA engine | Workflows | ||
| Named CRM integrations | Webhooks + Zapier | ||
| Free tier / trial | 7-day trial | 14-day trial | Free tier + trial |
Prices are the vendors' published entry-level paid plans as listed on their websites on August 1, 2026 (annual billing where noted). API-based platforms also pass through Meta's per-message fees, which vary by country and message category. Always confirm current pricing on each vendor's site.
The head-to-head, dimension by dimension
Pricing models: contacts vs conversations
These two bill in opposite currencies. Respond.io charges per plan, per user seat and per Monthly Active Contact: Growth at $199/mo includes 1,000 active contacts, then $12 per extra 100. Trengo charges per plan with allowances: Boost at EUR 299/mo (annual) includes 10 users and 6,000 conversations per year, Pro at EUR 499/mo includes 20 users and 18,000 conversations.
Trengo is notably more generous on seats for the price. But a busy inbox eats a yearly conversation allowance fast, and broadcasts cost extra on top. On Respond.io the equivalent surprise is a spike in active contacts. Meta message fees apply on both.
Edge: Trengo for seat-heavy support teams, Respond.io for contact-light automation.
Service tooling: tickets, SLAs and voice
If your team thinks in tickets, Trengo is the one actually built for you: ticketing-style workflows, SLA-oriented features, CSAT measurement and voice call support are native. Respond.io covers assignment and escalation through its workflow builder, which is powerful but is automation infrastructure rather than a service desk.
Edge: Trengo, clearly, for classic customer-service operations.
Automation and AI
Respond.io is ahead here. Its workflow automation is among the best on the API lane, and its AI agents handle lead qualification and support conversations with solid reporting behind them. Trengo ships an AI agent too, but automation depth and flexibility are not its center of gravity.
Edge: Respond.io for automation-first teams.
What both share: the Business API’s limits
Both platforms run WhatsApp through the official Business API, so both inherit its structure: a dedicated number (your existing number and history do not come along), Meta-approved templates outside the 24-hour window, per-message fees on top of subscriptions, and no access to WhatsApp groups at all.
Edge: tie. Structural API limits apply to both equally.
Choose Respond.io if...
- Sales automation, AI agents and workflows are the core job
- You run several channels and want deep, unified reporting
- Your contact volume is predictable enough for MAC billing
- HubSpot or Salesforce integration is a requirement
Choose Trengo if...
- You run a classic support team that needs SLAs and CSAT
- You want 10 to 20 seats included at a fixed plan price
- A European, GDPR-focused vendor matters to you
- Voice calls belong in the same inbox as chat
When neither fits: the no-API lane
Plenty of teams evaluating Respond.io and Trengo discover their actual blockers are the API lane itself: they want their existing WhatsApp number and history, they live in WhatsApp groups, or the per-message and per-seat math never stops growing. If that is you, Spun works with your existing WhatsApp number via QR code, with no Business API approval, no per-conversation fees and no template restrictions.
The whole team shares the number with unlimited members at a flat $50 to $200 per month, and AI does the actual inbox work: drafted replies, summaries of long threads, ask-a-chat, auto-labeling and automatic voice note transcription. Triage is AI-driven rather than a ticketing engine, which is honestly a different philosophy: if you need formal SLAs, Trengo is the better fit.
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