respond.io vs SleekFlow: which WhatsApp inbox fits your team in 2026?
respond.io and SleekFlow are both official WhatsApp Business API inboxes with AI agents, broadcasts and multi-channel support, and they look almost identical on a feature checklist. The real differences are in how they price contacts and seats, where the AI agent starts, and which regions each one serves best. This page sets them side by side with prices checked in October 2026.
Quick answer
Pick respond.io if you want deep workflows, 10 users on Growth and predictable pricing by contact tier, starting at $199 a month ($159 yearly) for the AI agent. Pick SleekFlow if you sell in Malaysia, Singapore, Hong Kong or Indonesia and want local-currency pricing, starting at US$139 a month (RM 449 in Malaysia) for Pro with AI. Meta's WhatsApp message fees are extra on both.
The short version
Both tools do the same core job well: put WhatsApp, website chat and social channels into one shared inbox on the official WhatsApp Business API, then add automation and an AI agent on top. The choice usually comes down to three things: where your business is, how many contacts you talk to each month, and how much workflow power you need.
respond.io
Strongest at workflows and routing. Price set by plan plus a monthly active contact tier. Growth includes 10 users and the AI agent. One global US dollar price list. 7-day trial with no card.
SleekFlow
Strongest at regional pricing and commerce tools in Asia. Price set per market in local currency, with contact and seat add-ons. Pro includes the AI agent and broadcasts. 7-day Pro trial with no card.
We build ReplyKit, a smaller WhatsApp agent that we mention once near the end. Both tools on this page are more capable than ours for teams that need broadcasts or the official API, and we say so where it matters.
Plans and prices side by side
On US dollar pricing, SleekFlow is cheaper at the bottom and similar at the top. respond.io's first plan with AI agents is Growth at $199 a month, while SleekFlow's is Pro at US$139.
| Tier | respond.io (monthly / yearly) | SleekFlow US (monthly / yearly) |
|---|---|---|
| Entry | Starter $99 / $79: 5 users, no AI agent | Essential $69 / $49: 3 seats, 500 contacts, no AI agent, rolling out by country |
| First plan with AI agent | Growth $199 / $159: 10 users, 1,000 contacts | Pro $139 / $109: 10 seats, 500 contacts |
| Upper tier | Advanced $349 / $279: 10 users, webhooks, SSO | Premium $349 / $279: 10 seats, 1,000 contacts, HubSpot and Zoho, webhooks |
| Enterprise | Custom | Custom |
| WhatsApp number fee | None listed | US$15 a month per number |
| Meta message fees | Extra, paid from a credit balance | Extra, by SleekFlow's rate card |
Prices checked October 2026 on respond.io's pricing page and SleekFlow's US pricing page. SleekFlow also sells a one-time 60-day onboarding package for Pro at US$999; it is included on Premium.
SleekFlow in local currency
SleekFlow's regional lists are not straight conversions. In Malaysia, Pro is RM 449 a month (RM 399 billed yearly) and includes 1,000 monthly active contacts and 3 seats; Premium is RM 1,399 (RM 1,199 yearly) with 3,000 contacts and 10 seats, and a WhatsApp number costs RM 50 a month. That is a very different shape from the US card, which gives 10 seats but only 500 contacts. respond.io has one dollar price list for everyone. Our SleekFlow pricing guide lists the other markets.
Contacts, seats and the meter that moves your bill
Both platforms charge by monthly active contacts: people you actually message in a billing month, not your whole list. The difference is how each charges once you go past the plan's allowance.
- respond.io picks a contact tier with the plan (1,000, 2,500, 5,000, 10,000 and above). If you go over, it bills extra contacts in blocks of 100: $12 per 100 on Growth, $15 on Advanced. Extra users are $12 to $24 a month depending on plan, on yearly billing.
- SleekFlow sells contact add-ons at US$20 per 100 on Pro and Premium, and seat add-ons at US$15 to US$25 a seat. In markets like Malaysia the starting contact allowance is higher, which matters more than the add-on price.
One more line item: both platforms pass on Meta's charges. Since 1 October 2026, Meta charges for service replies after the first 1,000 per business number each month, on top of the per-message charges for marketing and utility templates. Our explainer on WhatsApp Business API pricing covers the categories.
AI agents on each platform
Both include an AI agent from their middle plan, and both cap AI use with credits or fair use rather than charging per reply on self-serve plans.
| respond.io | SleekFlow | |
|---|---|---|
| Plan where the AI agent starts | Growth | Pro |
| AI on the entry plan | AI prompts and reply assist, 5,000 credits | Inbox co-pilot only (Essential) |
| How AI is metered | Credits from 10,000 on Growth, $15 per extra 1,000, fair use | Included on Pro, with integrations on Premium |
| AI acting in other systems | Through workflows and HTTP requests on Advanced | On Premium, "AI agent with integrations" |
In practice, the AI agent on either tool answers from knowledge you add, qualifies leads and hands chats to people. respond.io leans on its workflow builder to decide what happens next; SleekFlow leans on its Flow Builder and commerce integrations such as Shopify. Test both with your own ten hardest questions during the trials, because answer quality depends more on your content than on the brand.
One business, two monthly bills
Here is a hypothetical example: a home cleaning company with 4 staff answering chats, about 1,500 people messaging each month on one WhatsApp number, and an AI agent handling first replies. Monthly billing in US dollars.
| Line | respond.io Growth | SleekFlow Pro (US) |
|---|---|---|
| Plan | $199 (1,000 contacts, 10 users) | $139 (500 contacts, 10 seats) |
| Extra contacts to reach 1,500 | 5 blocks of 100 at $12 = $60 | 10 blocks of 100 at $20 = $200 |
| WhatsApp number | $0 | $15 |
| Platform total | $259 | $354 |
| Meta charges | Same on both: service replies beyond 1,000 a month plus any templates, at your market's rate | |
At 500 contacts the result flips: SleekFlow Pro is $154 with the number fee and respond.io Growth is still $199. And in Malaysia, SleekFlow Pro at RM 449 already includes 1,000 contacts, so a Malaysian business at 1,500 contacts would add 5 blocks rather than 10 (check the local add-on price in your checkout). The lesson: run the sum with your own contact count and your own market's price list before deciding on brand.
Pick respond.io if, pick SleekFlow if
Pick respond.io if
- You need detailed routing, lead stages and multi-step workflows.
- You have 5 to 10 people in the inbox and want them included in the plan.
- You sell in many countries and want one dollar price list.
- Your contact count sits just above a tier and $12 per 100 is cheaper than the next tier.
Pick SleekFlow if
- You are in Malaysia, Singapore, Hong Kong, Indonesia or the UAE and want local billing.
- You run a shop and want Shopify, catalog and payment link tools in the inbox.
- You have under 500 active contacts and want the cheapest plan with an AI agent.
- You want guided onboarding as a package.
If neither fits, our roundups of respond.io alternatives and SleekFlow alternatives list tools for smaller budgets.
A smaller third option
Both platforms are built for teams that run campaigns and need the official API. If your need is narrower, an AI that answers inbound WhatsApp and website enquiries, books appointments and passes hot leads to you, ReplyKit may be enough. It costs $29, $49 or $99 a month with AI replies included and no Meta fees.
The honest limits: ReplyKit connects by scanning a QR code as a linked device, which is an unofficial connection that Meta does not sanction, so a number can be restricted and we recommend a dedicated number. It replies only to people who message first, with no broadcasts, no Instagram or Messenger, and no integrations beyond CSV export. If you need any of those, choose respond.io or SleekFlow. If you only need fast answers, try ReplyKit free for 7 days before committing to a bigger platform.
Frequently asked questions
Is respond.io better than SleekFlow?
Neither is better for everyone. respond.io is stronger on workflows and includes 10 users on Growth, while SleekFlow is cheaper at low contact counts and offers local-currency pricing across Asia. Compare both with your own contact count and team size.
Which is cheaper, respond.io or SleekFlow?
For a team under 500 monthly active contacts, SleekFlow Pro at US$139 a month is cheaper than respond.io Growth at $199. Above about 1,000 contacts on US pricing, respond.io's $12 per 100 overage is usually cheaper than SleekFlow's US$20 per 100 add-on.
Do respond.io and SleekFlow charge WhatsApp fees?
Yes. Both pass on Meta's per-message charges for WhatsApp, which are not included in any plan. SleekFlow also charges a monthly fee per WhatsApp number, US$15 in the US or RM 50 in Malaysia.
Do both tools have a free trial?
Yes. respond.io offers a 7-day trial with Growth features and no credit card, and SleekFlow offers a 7-day Pro trial with no credit card. Neither has a permanent free plan for WhatsApp.
Can I move from SleekFlow to respond.io later?
Yes. Both use the official WhatsApp Business API, so you can migrate a number between providers, though you will need to rebuild flows, templates and AI knowledge. Export your contacts first and plan for a short changeover.
Do I need the official WhatsApp API at all?
You need it for broadcasts, templates to people who have not messaged you recently, and a verified business profile. If you only answer people who message you first, a simpler tool may be enough, with the trade-offs described in our API versus QR pairing guide.
Only need inbound answers and bookings?
ReplyKit answers WhatsApp and website chat from your own content, books appointments and flags hot leads. Start a 7-day free trial with no credit card.
Sources and further reading
- respond.io, Pricing · plans, users, contact overage, AI credits, trial and WhatsApp fee terms, checked October 2026
- SleekFlow, US pricing · Essential, Pro and Premium prices, contact and seat add-ons, number fee, checked October 2026
- SleekFlow, Malaysia pricing · RM prices, contact and seat allowances, RM 50 number fee, checked October 2026
- Meta, WhatsApp Business Platform pricing · per-message pricing and the service message free tier from 1 October 2026
ReplyKit is an independent product and is not affiliated with or endorsed by Meta or WhatsApp. Prices and features for other vendors are taken from their public pages as checked in October 2026 and may change. This article is general guidance, not financial or legal advice.