Zixflow VS Nullstack

Zixflow's answer

Choose Zixflow if your customers are on channels they reply to, like WhatsApp and RCS, and delivery matters to your business.

• Delivery you can trust: automatic fallback across channels. Shapoorji Pallonji sees 98% OTP delivery, and Kuku FM recovered 77% of messages that had failed.
• Replies get answered: AI agents respond in seconds, following your rules, with approve-first mode, discount limits and a full audit trail.
• One platform instead of several: OTPs, journeys, campaigns, AI agents and customer data in one place, with one bill.
• Honest reporting: delivery is reported per message, not just "submitted".

Zixflow may not be the right fit if you only use email. A dedicated email tool will likely serve you better.

Zixflow's answer

Zixflow is built for consumer brands whose customers are on channels that reply, like WhatsApp and RCS.

The main audiences are:

• D2C and ecommerce brands: cart recovery, COD confirmation, order updates and repeat orders
• Consumer apps: signup verification, onboarding, retention and win-back
• Banks and financial services: OTPs, transaction alerts and secure, compliant messaging

Within these companies, Zixflow is used by:

• Growth and marketing teams running journeys and campaigns
• Product and engineering teams sending OTPs and transactional messages through one API
• Support teams handling customer replies with AI agents and human handoff

Zixflow's answer

Zixflow started with a problem we kept seeing: businesses were losing customers in the gaps between their messaging tools, and nobody could see it.

A signup didn't go through because the OTP arrived late. A campaign reported 100,000 messages "sent" but reached far fewer people. A customer replied asking "COD available?" at 9 PM and never heard back.

None of this showed up as a failure on any dashboard, because each tool only reported its own part.

So we built Zixflow to run the whole journey in one place: verify the customer, reach them on the channel that works, answer every reply, and learn from every result. It runs on our own delivery infrastructure, so we can report what was actually delivered.

Today, Zixflow has delivered over 2 billion messages for more than 1,000 brands, including banks, consumer apps and D2C brands.

Zixflow's answer

• Tata Consumer Products
• Sharekhan
• Kuku FM
• TJSB Bank
• SDCC Bank
• Shapoorji Pallonji
• Seekho
• Purvankara
• IndoSpace

Zixflow's answer

Most businesses run customer messaging on three separate tools, and each one has a gap.

Messaging APIs send OTPs and alerts, but when an SMS fails, the customer is simply gone. Marketing tools send the same message to everyone and report "sent", not "delivered". Engagement tools were built before customers could reply, so when someone replies on WhatsApp, nobody answers.

Zixflow handles the full loop in one platform:

• Verify: one-tap login, or OTPs that fall back across SMS, RCS, WhatsApp and email until they land
• Engage: journeys that pick the message, timing and channel for each customer
• Reach: campaigns that try free channels first and fall back automatically
• Answer: AI agents that reply to customers in seconds, with human handoff
• Learn: every result feeds one customer profile, so the next message is smarter

Zixflow also runs on its own delivery infrastructure, and reports what was actually delivered, not just what was sent.