We used Oden to analyze Customer.io, Braze, Iterable, and Klaviyo using their public product pages, pricing docs, and G2 review data as of November 29, 2025. If you’re trying to pick a customer engagement platform, it’s hard to compare AI buzzwords, opaque pricing, and mixed reviews. This guide cuts through that by focusing on ratings, real-world strengths/weaknesses, and how each platform actually charges. By the end, you’ll know which tool fits your volume, channels, tech stack, and budget—not just which one has the flashiest homepage.

Which customer engagement platform has the best rating?

Below is a snapshot of G2 ratings and review counts (Marketing Automation / Customer Engagement categories) as of November 29, 2025.

Takeaways

• Klaviyo has the highest average rating (4.6) and a large sample size (1,100+ reviews), so its score is statistically robust—especially among ecommerce SMBs.(g2.com)
• Braze has the most reviews overall (1,400+), mostly from mid-market and enterprise customers, which makes its 4.5/5 rating meaningful at scale.(g2.com)
• Customer.io and Iterable both sit at 4.4/5 with hundreds of reviews, indicating broadly positive but more mixed feedback than Klaviyo or Braze.(g2.com)
• Because these ratings are close, differences in fit (channels, data model, pricing) matter more than a 0.1–0.2 rating gap.
• Review pools differ: Klaviyo skews ecommerce/retail, Braze and Iterable skew product-led/enterprise, Customer.io sits in between, so compare within your segment where possible.(g2.com)

How much do customer engagement platforms really cost?

Pricing here is directional. Actual quotes vary by region, volume, channels, and contract term.

*These are public list prices or third‑party estimates, not formal quotes.

What this means in practice

• Customer.io is the most transparent of the four: you can self-serve onto a paid plan starting at $100/mo and know exactly how profiles and email overages are billed.(customer.io)
• Braze and Iterable both live firmly in “enterprise pricing” territory, with opaque, MAU/profile-based quotes and contracts that commonly land in the mid–five to six figures annually once you’re sending at real volume.(encharge.io)
• Klaviyo offers the lowest-friction entry (a genuinely usable free plan and sub-$50 tiers) but becomes more expensive as your active profile count grows, especially with add-ons like Marketing Analytics or the Advanced Data Platform.(tekpon.com)
• For mid-market B2C and product-led B2B teams, Customer.io vs Iterable is often a realistic comparison; Braze is usually justified only when you have very large MAU counts and complex multi-channel needs.
• Pricing for all four will vary by region, channels, and contract length, and discounts are commonly negotiated at scale. Always double-check current prices with each vendor's calculator or sales team.

What are the key features of each platform?

Customer.io

Core positioning: Data-driven, multi-channel customer engagement for product-led teams that want fine-grained control over journeys and messaging.

Key Features:

• Full multi-channel campaigns: Email, SMS, push, in-app messages, webhooks, and even anonymous messages in a single workflow, aimed at behavior-based communication.(customer.io)
• Visual workflow builder: Drag-and-drop “Journeys” with branches, delays, conversion goals, and campaign triggers (event, segment, date, etc.).(customer.io)
• Deep personalization: Liquid templating, multi-language/localization, and no-code + code email editors for highly dynamic content.(customer.io)
• Strong data & integrations: 70+ integrations (Amplitude, Snowflake, Segment/Twilio Segment, Shopify, etc.) and a flexible data model including “objects” as well as people.(g2.com)
• Compliance & security: HIPAA (on higher tiers), SOC 2 Type II, GDPR, and CCPA support, plus SSO and role-based permissions.(customer.io)
• Omnichannel at scale: Case studies show tens of millions of monthly messages across email, SMS, push, and in-app for fintech and other high-volume apps.(customer.io)

Best For:

• Product-led SaaS and fintech teams that need behavioral, event-driven flows with strong data control.
• Mid-market companies that want enterprise-style capabilities without Braze/Iterable price tags.
• Orgs that care about HIPAA / compliance plus flexible integration with a modern data stack.
• Teams willing to invest in a powerful, slightly more technical tool to unlock sophisticated journeys.

Braze

Core positioning: Enterprise-grade, AI-powered customer engagement for brands that want to orchestrate sophisticated, real-time cross-channel experiences at massive scale.

Key Features:

• Comprehensive cross-channel messaging: Email, SMS, push, in-app, web, and emerging channels (RCS, WhatsApp commerce, carousels, etc.) on a unified platform.(braze.com)
• Canvas journey orchestration: Visual Canvas Flow for complex, conditional journeys across multiple channels with powerful audience segmentation.(g2.com)
• BrazeAI / Sage AI: AI decisioning, send-time optimization, content generation, and predictive models tightly integrated into the execution layer.(braze.com)
• Real-time data platform: Ingests events at scale, supports multi-cloud deployments (e.g., Azure), and integrates with warehouse/CDP tools via Braze Currents.(prnewswire.com)
• Mobile and gaming specialization: Mature mobile SDKs, in-app messaging, and even Unreal Engine SDK support for game experiences.(prnewswire.com)

Best For:

• Large B2C brands (retail, streaming, marketplaces, gaming) with millions of MAUs and complex cross-channel strategies.
• Teams with dedicated lifecycle, CRM, and data engineering resources who can fully leverage advanced segmentation and AI.
• Companies that need enterprise governance, multi-region deployment, and deep mobile/in-app capabilities.
• Organizations willing to commit to six-figure annual budgets in exchange for a market-leading engagement stack.(encharge.io)

Iterable

Core positioning: AI-powered customer activation platform for “moments-based marketing” across email, mobile, and web channels.

Key Features:

• Cross-channel delivery: Native support for email, SMS/MMS, push, in-app, embedded messaging, WhatsApp, and webhooks, marketed as “orchestrate moments across every channel.”(iterable.com)
• Iterable Studio journey builder: Modern, visual interface to design journeys that react to behavior in real time, with collaborative features.(globenewswire.com)
• Iterable AI Suite: Predictive audiences, send-time optimization, and generative tools (e.g., Journey Assist, Nova) baked into campaign and journey design.(g2.com)
• Strong data activation: Emphasis on unifying warehouse and product data using tools like Smart Ingest; robust integrations with Amplitude, Snowflake, Segment, etc.(g2.com)
• Customer activation focus: Official messaging centers on “joyful experiences” and harmonized, individualized communications, with 1,000+ brands using the platform.(globenewswire.com)

Best For:

• Digital-first B2C and B2B2C brands that want enterprise-grade cross-channel engagement but aren’t yet at Braze scale.
• Teams that value AI-assisted campaign design and warehouse-centric data strategies.
• Companies willing to pay premium pricing for modern UX and strong partner ecosystem (agencies, consultancies).
• Organizations that expect to grow toward high-volume email/SMS and multi-channel orchestration over the next few years.

Klaviyo

Core positioning: Unified customer platform and B2C CRM for ecommerce brands, focused on owned-email and SMS channels with built-in AI and analytics.

Key Features:

• Email + SMS-centric engagement: Strong flow builder and automation around ecommerce events (browse, cart, post-purchase) plus SMS, WhatsApp, forms, and reviews.(klaviyo.com)
• Unified customer profiles & analytics: CDP-like capabilities, RFM analysis, funnels, catalog insights, and Marketing Analytics add-on for deeper reporting.(g2.com)
• AI agents & assistants: K:AI Marketing Agent and Customer Agent for content generation and customer service, plus AI-powered SMS Assistant for faster copywriting.(klaviyo.com)
• Ecommerce-native integrations: 200–260+ native integrations (Shopify, Shopify Plus, Magento, WooCommerce, Gorgias, LoyaltyLion, etc.), geared toward DTC and retail.(daasity.com)
• Fast time-to-value: G2 data shows roughly 1 month median implementation, and the product is widely praised for ease of use for small teams.(g2.com)

Best For:

• Ecommerce and DTC brands that want deep storefront integrations, revenue-focused flows, and strong out-of-the-box templates.
• Small to mid-sized teams that need quick setup and intuitive UI more than maximum technical flexibility.
• Brands planning to lean heavily on email + SMS as primary revenue channels.
• Companies comfortable with profile-based billing and potential add-on costs in exchange for tightly integrated marketing + analytics.

What are the strengths and weaknesses of each platform?

Customer.io

Strengths:

• Powerful automation & flexibility: G2 reviewers consistently praise Customer.io’s ability to model complex journeys and segmentation with event-based triggers and intuitive flow builders.(g2.com)
• Strong multi-channel coverage: Email, SMS, push, in-app, and webhooks all live in one workflow, enabling Klar and others to run 17M+ monthly messages across four channels.(customer.io)
• Data-first approach: Case studies highlight how teams centralize data (e.g., BI integrations, custom dashboards) and then activate it in highly targeted campaigns.(customer.io)
• Support and rapid product evolution: Recent G2 reviews call out responsive support and rapid improvements to the visual builder and analytics.(g2.com)

Weaknesses:

• Learning curve & complexity: G2’s pros/cons list “Learning Curve” and “Missing Features” among top negatives; some users find the richness of options initially overwhelming.(g2.com)
• Performance at scale: A subset of reviewers mention UI slowness or lag when working with very large workspaces and campaigns.(g2.com)
• No native web push: Official docs confirm support for mobile push but not web push notifications, which can be a limitation for web-first products.(docs.customer.io)

Braze

Strengths:

• Best-in-class for mobile & in-app: Braze is frequently cited by practitioners (including Reddit growth and mobile marketers) as a top choice for in-app messaging, onboarding flows, and gamification.(reddit.com)
• Deep cross-channel orchestration: Users on G2 highlight the Canvas Flow and cross-channel capabilities as key advantages, allowing sophisticated multi-step journeys across email, push, SMS, and in-app.(g2.com)
• Enterprise-grade AI & data platform: Sage AI/BrazeAI is deeply embedded in the platform, and Braze has been repeatedly recognized as a Leader in Gartner’s Multichannel Marketing Hubs report.(investors.braze.com)
• Robust ecosystem & multi-cloud: Support for multiple clouds (including Azure), rich SDKs, and integrations position Braze well for global, regulated enterprises.(prnewswire.com)

Weaknesses:

• High cost and long implementation: G2 benchmarks show a ~4‑month median implementation and “$$$$$” perceived cost; multiple independent reviews estimate $60k–$200k+ per year for many deployments.(g2.com)
• Steep learning curve: “Learning Curve,” “Limitations,” and “Missing Features” rank among the top cons on G2, signaling that teams need training and process to get full value.(g2.com)
• Occasional reliability/complexity issues: A Reddit thread describes duplicate sends (emails/SMS) in some campaigns, reportedly tied to journey configuration and re-entry rules.(reddit.com)

Iterable

Strengths:

• Balanced enterprise feature set: G2 reviewers praise Iterable’s ease of use relative to its power, citing a good mix of cross-channel orchestration, segmentation, and testing tools.(g2.com)
• AI-forward roadmap: The AI Suite (predictive audiences, generative content, Journey Assist, Nova) is marketed heavily and surfaced directly in the UI, making AI features more accessible to marketers.(g2.com)
• Strong for mobile and SMS: Iterable emphasizes first-class mobile channels (push, in-app, embedded messaging, WhatsApp) with modern SDKs and global SMS partnerships.(iterable.com)
• Customer activation focus: Case studies show brands consolidating newsletters, triggered campaigns, and transactional messages into one platform, with significant lifts in engagement and open rates.(iterable.com)

Weaknesses:

• Premium, opaque pricing: Multiple independent comparisons note that Iterable does not publish pricing and typically lands in the tens-of-thousands+ per year, with entry points often around $1k–$3k/month.(getcensus.com)
• Reporting and feature gaps: G2 cons call out “Missing Features,” “Limited Features,” and “Inadequate Reporting” as recurring themes, especially for teams with advanced analytics needs.(g2.com)
• Non-trivial learning curve: While praised overall, some reviewers mention that mastering the full platform (especially data modeling and advanced workflows) requires significant time.(g2.com)

Klaviyo

Strengths:

• Outstanding fit for ecommerce: Klaviyo’s product description and partner ecosystem explicitly target ecommerce brands, with deep Shopify/Shopify Plus and Magento integrations and revenue-focused flows.(g2.com)
• High satisfaction and fast rollout: It has the highest G2 rating in this group (4.6/5) and a median implementation time of about one month, with users praising ease of creation and integrations.(g2.com)
• Rich analytics & CDP-like features: Add-ons like Marketing Analytics and the Advanced Data Platform provide deeper customer and product insights for segmentation and reporting.(help.klaviyo.com)
• Accessible entry-level pricing: A usable free plan and low starting tiers make Klaviyo attractive for new or smaller ecommerce stores.(tekpon.com)

Weaknesses:

• Cost escalates quickly with growth: Klaviyo’s move to active profile billing (including suppressed/unsubscribed contacts) and multiple paid add-ons can significantly increase costs as your list grows.(help.klaviyo.com)
• Perceived as expensive & support issues: G2 cons list “Expensive,” “Missing Features,” and “Poor Customer Support” among top negatives, particularly for larger or more complex users.(g2.com)
• Less ideal outside ecommerce: Official messaging and integrations overwhelmingly focus on online retail; teams with complex in-app or B2B workflows may hit limitations compared to Braze/Iterable/Customer.io.(businesswire.com)

How do these platforms position themselves?

Customer.io describes itself as a “leading customer engagement platform” for tech‑savvy organizations, emphasizing behavior-based, data-driven messaging across email, SMS, push, in-app, and webhooks.(g2.com) Its messaging stresses flexibility, developer-friendly integrations, and compliance, aiming squarely at product-led teams and mid-market companies that want control and transparency.

Braze markets itself as a comprehensive, AI-powered customer engagement platform that helps brands “rewrite the rules of customer engagement” and “Be Absolutely Engaging,” with data, AI, and cross-channel messaging in one place.(braze.com) Its target audience is large consumer brands that need real-time personalization at scale and are comfortable with enterprise-level investment.

Iterable positions as a “customer activation platform” focused on “moments-based marketing,” helping brands deliver “joyful experiences” with harmonized, individualized communications.(globenewswire.com) Marketing copy emphasizes AI-powered personalization, strong mobile capabilities, and a partner ecosystem aimed at scaling digital-first brands.

Klaviyo calls itself a “unified customer platform” and B2C CRM that gives online brands direct ownership of their consumer data and interactions, turning transactions into long-term relationships.(klaviyo.com) Its focus is clearly ecommerce: 100k–180k+ brands, heavy storefront integrations, and messaging about helping merchants “grow on their own terms.”

Which platform should you choose?

Choose Customer.io If:

1. You’re product-led (SaaS, fintech, marketplaces) and need granular, event-driven messaging—e.g., onboarding flows, lifecycle nudges, transactional updates—across email, SMS, push, and in-app in one builder.(customer.io)
2. You want transparent, scalable pricing with a clear link between profiles, email volume, and cost, and don’t want to negotiate opaque enterprise contracts yet.(customer.io)
3. Your data stack is modern and warehouse-centric, and you need strong integrations (e.g., Snowflake, Amplitude, Segment) plus support for custom objects.(g2.com)
4. Compliance matters (HIPAA/GDPR/CCPA) but you’re not a Fortune 100 giant—you want serious governance without Braze-level spend.(customer.io)
5. Your team is comfortable with more technical tools and willing to climb a learning curve to unlock highly tailored journeys and personalization.(g2.com)

Choose Braze If:

1. You’re a large B2C brand with millions of MAUs and a dedicated CRM/MarTech team, and you need best-in-class mobile, in-app, and cross-channel orchestration.(braze.com)
2. You’re willing to invest $60k–$200k+ per year in a customer engagement backbone and can justify multi-month implementation for long-term ROI.(encharge.io)
3. AI-driven decisioning at scale is strategic—you plan to lean on BrazeAI/Sage AI for personalization, experimentation, and optimization across channels.(investors.braze.com)
4. You have complex data and compliance requirements (multi-region, multi-cloud, strict SLAs) and need a vendor that already operates at global enterprise scale.(prnewswire.com)
5. Mobile and gaming experiences are core to your product, and you want advanced SDKs (including Unreal Engine) and rich in-app experiences out of the box.(prnewswire.com)

Choose Iterable If:

1. You’re a fast-growing digital brand (mid-market or upper-SMB) that needs enterprise-grade cross-channel engagement without fully jumping into Braze’s cost tier.(g2.com)
2. You want AI-native marketing execution—predictive segments, generative journey design (Journey Assist), and optimization tools integrated into the workflow builder.(g2.com)
3. Your team prefers modern UX and low-code workflows, with the ability to design journeys and experiments quickly while data teams connect warehouses via tools like Smart Ingest.(globenewswire.com)
4. Budget is flexible but not unlimited—you can handle a custom quote in the mid–five figures annually, but you still expect clear value from cross-channel and AI capabilities.(getcensus.com)
5. You want a strong solutions-partner ecosystem (agencies, consultants) to help with strategy, implementation, and optimization.(iterable.com)

Choose Klaviyo If:

1. You’re an ecommerce or DTC brand on Shopify, Shopify Plus, Magento, WooCommerce, or similar, and you want your engagement platform to “speak ecommerce” natively.(daasity.com)
2. You need to get started quickly with a small team, leveraging templates and flows that can be implemented in weeks, not months.(g2.com)
3. Email and SMS are your primary revenue channels, and you want powerful automation, A/B testing, and analytics built around campaigns like welcome, cart recovery, and post-purchase.(klaviyo.com)
4. You value low-friction entry pricing (including a free tier) but accept that costs will rise as your active profile count and add-on usage increase.(tekpon.com)
5. You’re comfortable with a marketing stack centered on Klaviyo as your B2C CRM/CDP, using its 200+ integrations and analytics instead of cobbling together multiple tools.(businesswire.com)

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Sources & links

### Company Websites
- Customer.io – Product & Platform Overview (https://customer.io/platform)
- Braze – Customer Engagement Platform Homepage (https://www.braze.com/)
- Iterable – Product Overview (https://iterable.com/product/)
- Klaviyo – Unified Customer Platform Homepage (https://www.klaviyo.com/)

### Pricing Pages
- Customer.io – Pricing (https://customer.io/pricing/)
- Customer.io – Billing Model Docs (https://docs.customer.io/accounts-and-workspaces/how-we-bill/)
- Klaviyo – Billing & Pricing Docs (https://help.klaviyo.com/hc/en-us/articles/115000976672)
- Third-Party Braze Pricing Analysis – Encharge (https://encharge.io/braze-review/)
- Third-Party Iterable Pricing Analysis – Sender (https://www.sender.net/reviews/iterable/pricing/)
- Third-Party Klaviyo Pricing Reviews – Tekpon (https://tekpon.com/software/klaviyo/pricing/)

### Documentation
- Customer.io – Marketing Automation Features (https://customer.io/features/)
- Customer.io – Message Channels Setup (https://docs.customer.io/get-started/set-up-messages/)
- Iterable – Cross-Channel Delivery (https://iterable.com/product/deliver/)
- Klaviyo – Product & Feature Docs (https://www.klaviyo.com/product)

### G2 Review Pages
- G2 – Customer.io (https://www.g2.com/products/customer-io/reviews)
- G2 – Braze (https://www.g2.com/products/braze/reviews)
- G2 – Iterable (https://www.g2.com/products/iterable/reviews)
- G2 – Klaviyo (https://www.g2.com/products/klaviyo/reviews)

### Reddit Discussions
- r/marketing – Braze Duplicate Sends Discussion (https://www.reddit.com/r/marketing/comments/1bpk1lx)
- r/GrowthHacking – Tools for App Engagement (Braze praised for in-app) (https://www.reddit.com/r/GrowthHacking/comments/1nwq04q)

### Additional Resources
- Iterable – Customer Activation Positioning Press Release (https://www.globenewswire.com/news-release/2022/06/23/2468065/0/en/Iterable-Surpasses-1-000-Customers-Using-Its-Platform-Around-the-World.html)
- Braze – AI & Product Announcements (https://investors.braze.com/news/)
- Klaviyo – Newsroom & Product Announcements (https://www.klaviyo.com/newsroom)
- Customer.io – Case Studies (https://customer.io/learn/case-studies/)