Who is Knock best for?

Knock is built for Software engineers and backend developers building product notification systems, Engineering leads and VPs of Engineering at SaaS companies, Product managers at product-led growth companies, Marketing operations teams managing lifecycle and campaign messaging. Common use cases include Product notification systems (user invites, activity alerts, access requests); Transactional and lifecycle messaging across email, push, and SMS; In-app notification feeds, inboxes, and real-time toasts.

Knock offers three tiers. Developer (free): up to 10,000 messages/month, 500 guide active users, 500 AI agent credits, unlimited workflows and channels, 99.9% uptime SLA. Starter ($250/month): 50,000 messages included ($0.005 per additional), 2,500 guide active users ($0.05 per additional), 2,000 AI agent credits, removes Knock branding. Enterprise (contact sales): flexible volume-based or monthly notified-user pricing, annual commit discounts, dedicated infrastructure, HIPAA BAA, SAML 2.0 SSO, SCIM directory sync, Datadog/warehouse analytics streaming, 90-day log retention, and enterprise SLAs. Knock does not charge for workflow triggers or recipients—only for messages successfully sent.

What are the alternatives to Knock?

Common Communications APIs alternatives to Knock include Twilio, Novu, Resend, Mailgun, Vonage. See the full comparison hub at /verticals/communications-apis/compare.

What do users praise about Knock?

Users frequently praise: Clean, well-documented APIs; Fast time-to-implement (hours not weeks); Visual workflow builder with batching and delay logic; Responsive customer support and Slack support channel; Empowers non-technical team members to manage notifications; Reliable, production-grade infrastructure; Rich in-app notification feed and UI components; Centralizes multi-channel notifications in one platform.

What are common complaints about Knock?

Frequently cited limitations: Missing features flagged by multiple reviewers; Limited template creation options; Weak campaign performance analytics; Golang SDK quality and typing issues; Learning curve for advanced workflow configurations; Notification delivery issues noted by some users; No declarative workflow definition (e.g., Terraform provider); Customers still pay separately for downstream channel providers.

When was Knock founded and where?

Knock was founded in 2021, headquartered in Brooklyn, New York, US by Sam Seely, Chris Bell.

AI visibility report

Knock ranks #2 in Communications APIs AI search.

Outside the top three on 14 of the 25 prompts buyers actually ask.

Twilio is cited on 11 of those losses.

25 prompts

6 platforms

Updated Sep 4, 2026 - refreshed weekly

Track Knock daily

Free trial. Setup comes pre-filled for Knock.

Track Knock across these prompts daily.

Start free trial

18percent

Presence Rate

Low presence

#2 among 12 vendors · still absent from 82% of tracked prompt responses

Top-3 citations across 150 prompt × platform pairs

+0.30

Sentiment

-1.00.0+1.0

Positive

#2of 12

Peer Ranking

#1#12

Top tierin Communications APIs

Key Metrics

Presence Rate

18.0%

Share of Voice

17.1%

Avg Position

#25.2

Docs Presence

9.3%

Blog Presence

10.0%

Brand Mentions

26.0%

Platform Breakdown

Grok

60%15/25 prompts

ChatGPT

Research dossierCapabilities, use cases, sources, reviews, pricing, and FAQ

Overview

Knock (knock.app) is a developer-first notification infrastructure and customer engagement platform founded in 2021 and headquartered in Brooklyn, New York. Built by Sam Seely and Chris Bell—previously engineering and product leaders at Frame.io—Knock provides a unified API, workflow engine, and UI component library that enables SaaS product teams to orchestrate cross-channel notifications across email, SMS, push, in-app feeds, and chat without building and maintaining custom infrastructure. Knock delivers hundreds of millions of messages per month and is used in production by companies including Vercel, Amplitude, Webflow, Medium, Discogs, and Clay. The platform is SOC 2, HIPAA, GDPR, and CCPA compliant with a stated 99.99% uptime target.

Knock is notification infrastructure and customer engagement software that gives engineering and product teams a single platform to design, orchestrate, and deliver cross-channel messaging. Its core primitives include a visual workflow editor with batch, delay, branch, throttle, and AI agent step functions; an in-app UI component library (feeds, toasts, guides); a broadcast tool for one-time campaigns; a preference and unsubscribe management system; and a developer toolkit (CLI, CI/CD integration, MCP server, SDKs in 8 languages). Knock acts as an orchestration layer on top of downstream email, SMS, push, and chat providers rather than replacing them.

AI visibility report

Knock ranks #2 in Communications APIs AI search.

Outside the top three on 14 of the 25 prompts buyers actually ask.

Twilio is cited on 11 of those losses.

25 prompts

6 platforms

Updated Sep 4, 2026 - refreshed weekly

Track Knock daily

Free trial. Setup comes pre-filled for Knock.

Track Knock across these prompts daily.

Start free trial

18percent

Presence Rate

Low presence

#2 among 12 vendors · still absent from 82% of tracked prompt responses

Top-3 citations across 150 prompt × platform pairs

+0.30

Sentiment

-1.00.0+1.0

Positive

#2of 12

Peer Ranking

#1#12

Top tierin Communications APIs

Key Metrics

Presence Rate

18.0%

Share of Voice

17.1%

Avg Position

#25.2

Docs Presence

9.3%

Blog Presence

10.0%

Brand Mentions

26.0%

Platform Breakdown

Grok

60%15/25 prompts

ChatGPT

Research dossierCapabilities, use cases, sources, reviews, pricing, and FAQ

Overview

Reviews

4.6/5G2·144+

Praised

Clean, well-documented APIs
Fast time-to-implement (hours not weeks)
Visual workflow builder with batching and delay logic
Responsive customer support and Slack support channel
Empowers non-technical team members to manage notifications
Reliable, production-grade infrastructure
Rich in-app notification feed and UI components
Centralizes multi-channel notifications in one platform

Criticized

Missing features flagged by multiple reviewers
Limited template creation options
Weak campaign performance analytics
Golang SDK quality and typing issues
Learning curve for advanced workflow configurations
Notification delivery issues noted by some users
No declarative workflow definition (e.g., Terraform provider)
Customers still pay separately for downstream channel providers

Knock holds a 4.6/5 rating across 144 G2 reviews (81% five-star), praised primarily for its clean and well-documented APIs, fast time-to-implement, powerful visual workflow builder, and highly responsive customer support. Product Hunt reviewers highlight reliability and breadth of features including templating, scheduling, in-app feeds, and out-of-the-box integrations. Common criticisms include missing features flagged by some reviewers, limited campaign performance analytics compared to full marketing platforms, and some SDK quality gaps (notably the Go client). Overall sentiment is strongly positive, with users frequently citing that Knock replaced weeks of custom engineering work.

Prompt	Gemini Search	Google AI Mode	Bing Copilot	ChatGPT	Perplexity	Grok
Capability2/5 cited (40%)
What transactional email APIs handle very high-volume bulk sends alongside triggered one-to-one emails without separate infrastructure?	A competitor was cited	Neither your brand nor a competitor was cited	A competitor was cited	A competitor was cited	Neither your brand nor a competitor was cited	Your brand and a competitor were cited

#	Brand	PresencePres.	Share of VoiceSoV	DocsDocs	BlogBlog	MentionsMent.	Avg PosPos	Sentiment
1	Twilio	20.7%	22.5%	13.3%	0.0%	56.0%	#35.8	+0.45
2	Knock	18.0%	17.1%	9.3%	10.0%	26.0%	#25.2	+0.30
3	Novu	9.3%	11.3%	5.3%	0.0%	24.7%	#49.8	+0.29
4	Resend	8.7%	4.3%	0.0%	8.0%	16.0%	#23.1	+0.31
5	Vonage	7.3%	8.1%	2.0%	0.7%	24.7%	#37.3	+0.40
6	Mailgun	7.3%	8.4%	1.3%	3.3%	0.0%	#37.9	+0.31
7	Sinch	6.7%	6.1%	0.0%	2.7%	0.7%	#20.5	+0.37
8	Postmark	5.3%	8.4%	1.3%	3.3%	24.0%	#38.3	+0.29
9	Stream	4.0%	5.8%	0.0%	2.7%	12.0%	#28.4	+0.56
10	Plivo	4.0%	5.8%	2.0%	2.7%	16.0%	#51.4	+0.28
11	Bird	2.0%	2.0%	0.0%	0.0%	0.0%	#15.6	+0.70
12	Nylas	0.7%	0.3%	0.0%	0.0%	1.3%	#1.0	+0.80

Developer Experience4/5 cited (80%)
Which communications API platforms are least opinionated about the user data model and easiest to integrate with an existing user table?	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Your brand was cited	Neither your brand nor a competitor was cited	A competitor was cited

Integrations & Ecosystem3/5 cited (60%)
Which communications APIs integrate best with CRMs and marketing automation tools so sales teams can see notification history alongside customer records?	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	A competitor was cited	Neither your brand nor a competitor was cited	A competitor was cited

Performance & Reliability3/5 cited (60%)
What tools help load test a notification system to ensure it handles a burst of 1 million emails without queue buildup?	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	A competitor was cited

Knock ranks #2 in Communications APIs AI search.

Key Metrics

Platform Breakdown

Overview

Knock ranks #2 in Communications APIs AI search.

Key Metrics

Platform Breakdown

Overview

Prompts where competitors are visible and Knock is not.

Where Knock is winning5

Where Knock is losing5

Key Facts

Key Capabilities10

Key Use Cases8

Knock customer outcomes

Recent Trend

How AI describes Knock3

Most cited sources8

Alternatives in Communications APIs6

Reviews

Pricing

Limitations

Topic Coverage

Prompt-Level Results

Vertical Ranking

Turn this into your team dashboard

Frequently asked questions

Setup & First Run4/5 cited (80%)
Which SMS API providers make it easiest to migrate sending infrastructure without breaking existing 2FA flows for users?	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	Neither your brand nor a competitor was cited	A competitor was cited	Neither your brand nor a competitor was cited	Your brand and a competitor were cited

Knock ranks #2 in Communications APIs AI search.

Key Metrics

Platform Breakdown

Overview

Knock ranks #2 in Communications APIs AI search.

Key Metrics

Platform Breakdown

Overview

Prompts where competitors are visible and Knock is not.

Where Knock is winning5

Where Knock is losing5

Key Facts

Key Capabilities10

Key Use Cases8

Knock customer outcomes

Recent Trend

How AI describes Knock3

Most cited sources8

Alternatives in Communications APIs6

Reviews

Pricing

Limitations

Topic Coverage

Prompt-Level Results

Vertical Ranking

Turn this into your team dashboard

Frequently asked questions

What does Knock do?

Who is Knock best for?

How is Knock priced?

What are the alternatives to Knock?

What do users praise about Knock?

What are common complaints about Knock?

When was Knock founded and where?

How big is Knock?