Comparison
Overview
Company snapshot and where each provider is based.
| Field | Prelude | Rule |
|---|---|---|
| What it is | Developer platform for phone and email verification (OTP), authentication, number intelligence, and anti-fraud onboarding delivered across SMS, RCS, WhatsApp, voice and other channels. | Swedish marketing automation platform (Rule Communication Nordic AB) for email, SMS and RCS campaigns, with a REST API for transactional message sending. |
| Founded | 2022 | 2007 |
| Ownership | private | private |
| Employees | 51-200 | 10-50 |
| HQ city | Paris | Stockholm |
| HQ country | France (EU) | Sweden (EU) |
What's the differencePrelude edges ahead on the overall messaging.dev Score (62 vs 28). Prelude is private and headquartered in Paris, France (EU); Rule is private and based in Stockholm, Sweden (EU).
Channels
Which messaging channels each provider can send and receive on.
| Field | Prelude | Rule |
|---|---|---|
| SMS | Yes | Yes |
| MMS | No | No |
| RCS | Yes | Yes |
| Yes | No | |
| Viber | Yes | No |
| Facebook Messenger | No | No |
| Telegram | Yes | No |
| Apple Messages for Business | No | No |
| Voice | Yes | No |
| Yes | Yes |
What's the differenceThey share 3 channels. Prelude additionally offers WhatsApp, Viber, Telegram, Voice.
Developer Experience
How quickly a developer can sign up and send a first message.
| Field | Prelude | Rule |
|---|---|---|
| Self-service onboarding | Yes | Yes |
| Free developer credit | No | No |
| Docs quality | high | med |
| Documentation | Open ↗ | Open ↗ |
| SDKs | Node.js, Python, Go, Java, Ruby, PHP, C# | Node.js, PHP |
| Sandbox / test env | No | No |
| API types | REST | REST |
What's the differenceOn SDKs, Prelude adds Python, Go, Java, Ruby, C#.
Data & Compliance
Data residency options and enterprise compliance certifications.
| Field | Prelude | Rule |
|---|---|---|
| EU data residency | Yes | Yes |
| US data residency | No | No |
| Choose region | No | No |
| GDPR | Yes | Yes |
| ISO 27001 | Yes | No |
| SOC 2 | Yes | No |
| HIPAA | No | No |
What's the differencePrelude offers ISO 27001, while Rule does not; Prelude offers SOC 2, while Rule does not.
Data Retention
How long message content and metadata are stored, and whether that is configurable.
| Field | Prelude | Rule |
|---|---|---|
| Retention policy | Not publicly documented in detail. Prelude is a European (Paris-based) company that hosts and processes data in EU data centers under GDPR, with SOC 2 Type 2 and ISO 27001:2022 controls including encryption of data in transit and at rest. It states that only essential data is stored for delivery tracking, but specific message-content and metadata retention periods are not published on the site or trust center. | Privacy policy states Rule only works with partners that process personal data within the EU/EEA (or that maintain an equivalent level of protection), keeps data only as long as a customer relationship exists or it remains relevant, and does not use marketing data older than 3 years. No specific retention period for message content or logs is publicly documented. |
What's the differencePrelude: Not publicly documented in detail. Prelude is a European (Paris-based) company that hosts and processes data in EU data centers under GDPR, with SOC 2 Type 2 and ISO 27001:2022 controls including encryption of data in transit and at rest. It states that only essential data is stored for delivery tracking, but specific message-content and metadata retention periods are not published on the site or trust center. Rule: Privacy policy states Rule only works with partners that process personal data within the EU/EEA (or that maintain an equivalent level of protection), keeps data only as long as a customer relationship exists or it remains relevant, and does not use marketing data older than 3 years. No specific retention period for message content or logs is publicly documented.
Pricing & Credits
Pricing model and the cost of a first message.
| Field | Prelude | Rule |
|---|---|---|
| Pricing model | Pay-as-you-go per-verification pricing plus at-cost (zero-markup) per-message charges, with optional Startup subscription and custom Enterprise tiers. | Subscription tiers by contact-list size (free 250-contact plan without SMS, Professional from €595/month for 2,500 contacts, custom Enterprise) plus per-message SMS/RCS fees; a standalone SMS/RCS plan with unlimited contacts costs €100/month plus per-message rates. |
| SMS starting price | €0.0043 per SMS (US, at-cost); verification fee from €0.032 | From €0.04 per SMS (0.40 SEK per SMS in Sweden), on top of the monthly plan |
| Free developer credit | No | No |
What's the differencePrelude and Rule are closely matched on pricing & credits — no material differences in the tracked fields.
Reach & Reliability
Global coverage and delivery dependability.
| Field | Prelude | Rule |
|---|---|---|
| Countries covered | 230 | 0 |
| Direct operator connections | Yes | No |
| Published uptime SLA | No published SLA | No published SLA |
What's the differencePrelude leads on Countries covered (230 vs 0 for Rule); Prelude offers Direct operator connections, while Rule does not.
Company & Trust
Independent reviews and company profile.
| Field | Prelude | Rule |
|---|---|---|
| G2 rating | 4.9 | 4.5 |
| G2 reviews | 13 | 9 |
| Ownership | private | private |
| Employees | 51-200 | 10-50 |
What's the differencePrelude leads on G2 rating (4.9 vs 4.5 for Rule); Prelude leads on G2 reviews (13 vs 9 for Rule).
Still deciding? Read the quickstart guides: