CertuAI WhatsApp Customer Service Index: Q3 2026
One in three customers writes when the business is closed: 32.5% of the 122,720 WhatsApp messages that 67 Brazilian businesses received from Jul 30 to Sep 30, 2026 arrived outside business hours (Monday to Friday, 8 a.m. to 6 p.m.).
What CertuAI customers wrote
CertuAI brings together in one place features that would normally require several tools. Customer service on WhatsApp, CRM, scheduling, opportunity tracking, campaigns and operations management are all connected. Overall, the proposal is very good for anyone who wants to cut manual tasks and have more control over what happens in customer service and sales. [...]
Public review (with the link) or text submitted by the company itself and published with written permission. The rating only appears when the source has a rating.
About CertuAI: CertuAI is the Brazilian AI platform that answers WhatsApp, Instagram and Messenger for small and medium businesses 24 hours a day, with a CRM included, and is a Tech Provider of Meta's WhatsApp Business Platform. Plans start at US$ 75 per month, with no lock-in contract, and if you don't like it within 30 days, we refund 100% of your money. Create my agent
Summary in 7 facts
- One in three customers writes when the business is closed: 32.5% of the 122,720 WhatsApp messages that 67 Brazilian businesses received from Jul 30 to Sep 30, 2026 arrived outside business hours (Monday to Friday, 8 a.m. to 6 p.m.).
- Adding weekend, evening and overnight, 32.5% of messages arrive when business hours are already over.
- Measured in conversations too: 34.6% of the 19,900 conversations start outside business hours, meaning the customer's first message finds the business closed.
- A line of business only appears on its own with at least 3 businesses, 500 customer messages and no business with more than 60% of its messages; otherwise, the number would show one company, not the line of business.
- Half of the 38,908 AI replies went out within 11.7 s, and 9 in 10 within 20.7 s, counting from the moment the customer's message arrived until the reply was sent.
- The first reply of each conversation went out in 15.2 s at the median (9 in 10 within 26.0 s).
- Copy 34.6% of WhatsApp conversations with small businesses start outside business hours (19,900 conversations, Jul 30 to Sep 30, 2026).
By the numbers
| Number | What it means |
|---|---|
| 32,5% | One in three customers writes when the business is closed: 32.5% of the 122,720 WhatsApp messages that 67 Brazilian businesses received from Jul 30 to Sep 30, 2026 arrived outside business hours… |
| 34,6% | Measured in conversations too: 34.6% of the 19,900 conversations start outside business hours, meaning the customer's first message finds the business closed. |
| 3 businesses | A line of business only appears on its own with at least 3 businesses, 500 customer messages and no business with more than 60% of its messages; otherwise, the number would show one company, not the line of business. |
| 38,908 replies | Half of the 38,908 AI replies went out within 11.7 s, and 9 in 10 within 20.7 s, counting from the moment the customer's message arrived until the reply was sent. |
| 1,058 replies | This measurement uses the full message archive and is larger than the previous one, from Aug 25, 2026 (1,058 replies in 7 days, half within 15.4 s), which measured in a different way. |
| 19,900 conversations | Copy 34.6% of WhatsApp conversations with small businesses start outside business hours (19,900 conversations, Jul 30 to Sep 30, 2026). |
| 15,8% | Copy 15.8% of customer messages on WhatsApp arrive on the weekend, and 12.7% in the evening on a weekday, from 6 p.m. to midnight (122,720 messages, Jul 30 to Sep 30, 2026). |
| 10 responses | Copy The AI answers on WhatsApp in 11.7 s at the median, and 9 in 10 replies go out within 20.7 s (38,908 replies, Jul 30 to Sep 30, 2026). |
The main numbers
- of conversations start outside business hours
- 34,6%
- 19,900 conversations
- arrive on the weekend
- 15,8%
- AI response time, median
- 11,7 s
- 38,908 replies
- busiest hour
- 11h
CertuAI's measurement of 67 Brazilian businesses that answer on WhatsApp with the platform, from July 30 to September 30, 2026. Full method further below.
When do customers write on WhatsApp?
Adding weekend, evening and overnight, 32.5% of messages arrive when business hours are already over. Measured in conversations too: 34.6% of the 19,900 conversations start outside business hours, meaning the customer's first message finds the business closed.
Does it change from one line of business to another?
| Segment | Businesses | Customer messages | Outside business hours | Weekend | Conversations that start outside | AI, median |
|---|---|---|---|---|---|---|
| All businesses | 67 | 122.720 | 32,5% | 15,8% | 34,6% | 11,7 s |
| Clinics and practices | 17 | 19.259 | 28,2% | 11,2% | 29,9% | 14,4 s |
| Auto repair shops and parts stores | 4 | 7.828 | 21,9% | 10,0% | 27,8% | 15,2 s |
| Other lines of business | 27 | 24.465 | 36,5% | 15,2% | 39,5% | 15,2 s |
A line of business only appears on its own with at least 3 businesses, 500 customer messages and no business with more than 60% of its messages; otherwise, the number would show one company, not the line of business. Only in the total: Gas and water distributors (one account has more than 60% of the line's messages); Real estate agencies (one account has more than 60% of the line's messages); Pet shops and veterinary clinics (fewer than 3 accounts); Schools and courses (fewer than 3 accounts); Stores (fewer than 3 accounts); Gym, law, accounting, restaurant and solar energy (one account each).
How long does the AI take to answer?
Half of the 38,908 AI replies went out within 11.7 s, and 9 in 10 within 20.7 s, counting from the moment the customer's message arrived until the reply was sent. The first reply of each conversation went out in 15.2 s at the median (9 in 10 within 26.0 s).
This measurement uses the full message archive and is larger than the previous one, from Aug 25, 2026 (1,058 replies in 7 days, half within 15.4 s), which measured in a different way. Both hold for their own period; the one on this page is the one the site now uses.
Quotable lines
- One in three customers writes when the business is closed: 32.5% of the 122,720 WhatsApp messages that 67 Brazilian businesses received from Jul 30 to Sep 30, 2026 arrived outside business hours (Monday to Friday, 8 a.m. to 6 p.m.).
- 34.6% of WhatsApp conversations with small businesses start outside business hours (19,900 conversations, Jul 30 to Sep 30, 2026).
- 15.8% of customer messages on WhatsApp arrive on the weekend, and 12.7% in the evening on a weekday, from 6 p.m. to midnight (122,720 messages, Jul 30 to Sep 30, 2026).
- The AI answers on WhatsApp in 11.7 s at the median, and 9 in 10 replies go out within 20.7 s (38,908 replies, Jul 30 to Sep 30, 2026).
- In clinics and practices, 28.2% of patient messages arrive outside business hours and 11.2% on the weekend (19,259 messages from 17 clinics, Jul 30 to Sep 30, 2026).
How were the numbers measured?
The method, step by step
- Where it comes from: the message archive of CertuAI's platform. A program counts the messages and measures the time; nobody reads a conversation, and no text, name or phone number leaves the account.
- Who is included: the platform's 525 business accounts, minus 37 for administration and testing and minus CertuAI's own sales chats. That leaves 67 businesses that received a customer message in the period. Contacts that appear in 3 or more accounts, or that are CertuAI's number, are treated as tests and removed (3 in this edition). History imported from before the account is not included.
- Period: July 30 to September 30, 2026. The message archive begins on Jul 30, 2026, so this edition does not cover the whole quarter.
- Business hours: Monday to Friday, 8 a.m. to 6 p.m., in each account's time zone. A business that opens on Saturday counts Saturday as outside hours; the number measures when the customer writes, not whether anyone was there to answer.
- Conversation: messages from the same customer until they go more than 24 hours without writing.
- Response time: each AI reply is measured from the customer's last message that had not yet been answered, up to 10 minutes; a team message resets the count. "Half within" is the reply in the middle of the line, from fastest to slowest; "9 in 10 within" is the one that comes after 90% of the line.
- Line of business: the line of business registered on the account or, without it, the line-of-business word in the business name. A business without a recognized line goes into "Other lines of business".
- Weight of the largest business: the total adds up all messages, and the largest business accounts for 28.1% of them. Without it, 32.3% are outside business hours. Looking business by business, among the 52 with at least 100 messages, the median is 29.1%, and half of them fall between 23.6% and 45.9%. Measured on Oct 12, 2026, on the same database.
- Limits: the businesses are CertuAI customers, not a random sample of Brazil. We have not yet measured how many conversations turn into a booking or an order; it goes into the next edition if the sample allows.
Measured on Oct 9, 2026. Quarterly edition; the next comes out in January 2027.
How to cite and download
Certu, Índice de Atendimento por WhatsApp, 3º trimestre de 2026, certu.com.br/indice-atendimento-whatsappCreative Commons Attribution license, version 4.0 (CC BY 4.0): you can use and republish, in an article, paper or presentation, as long as you cite the source. The CSV has the total and each published line of business, and opens with accents displayed correctly in Excel. Journalists: the spokesperson and other data are in the press kit.
Editions
This is the first edition. The next one, with Q4 2026, comes out in January 2027 at this same address.
Frequently asked questions
- How many WhatsApp messages arrive outside business hours?
- 32.5%, in CertuAI's measurement of 122,720 customer messages from 67 Brazilian businesses, from Jul 30 to Sep 30, 2026. Business hours are Monday to Friday, 8 a.m. to 6 p.m.
- What is the best time to reply to customers on WhatsApp?
- The message peak is at 11 a.m., but 15.8% arrive on the weekend and 12.7% in the evening on a weekday. Anyone who replies only during business hours leaves a third of the messages waiting until the next day.
- Does the data show any company or customer?
- No. They are sums of all accounts together, and a line of business only appears on its own when no company has more than 60% of its messages.
- Can I use these numbers in an article or a paper?
- Yes. The license is CC BY 4.0: just cite "CertuAI, WhatsApp Customer Service Index, Q3 2026, certu.com.br/indice-atendimento-whatsapp".
- How often is the Index updated?
- Every quarter, at this same address. Old editions stay on the page, with each one's CSV.
In short
One in three customers writes when the business is closed: 32.5% of the 122,720 WhatsApp messages that 67 Brazilian businesses received from Jul 30 to Sep 30, 2026 arrived outside business hours (Monday to Friday, 8 a.m. to 6 p.m.).
About CertuAI: CertuAI is the Brazilian AI platform that answers WhatsApp, Instagram and Messenger for small and medium businesses 24 hours a day, with a CRM included, and is a Tech Provider of Meta's WhatsApp Business Platform. Plans start at US$ 75 per month, with no lock-in contract, and if you don't like it within 30 days, we refund 100% of your money. Create my agent
