Comparison

Overview

Company snapshot and where each provider is based.

FieldPreludeSmstools
What it isDeveloper platform for phone and email verification (OTP), authentication, number intelligence, and anti-fraud onboarding delivered across SMS, RCS, WhatsApp, voice and other channels.Belgian business-messaging platform by Xtreme Internet Solutions offering an SMS gateway API, bulk SMS marketing software, WhatsApp Business API, voice messages and email-to-SMS with EU-only hosting.
Founded20222004
Ownershipprivateprivate
Employees51-2001-10
HQ cityParisDilsen-Stokkem
HQ countryFrance (EU)Belgium (EU)
What's the differencePrelude edges ahead on the overall messaging.dev Score (62 vs 56). Prelude is private and headquartered in Paris, France (EU); Smstools is private and based in Dilsen-Stokkem, Belgium (EU).

Channels

Which messaging channels each provider can send and receive on.

FieldPreludeSmstools
SMSYesYes
MMSNoNo
RCSYesNo
WhatsAppYesYes
ViberYesNo
Facebook MessengerNoNo
TelegramYesNo
Apple Messages for BusinessNoNo
VoiceYesYes
EmailYesNo
What's the differenceThey share 3 channels. Prelude additionally offers RCS, Viber, Telegram, Email.

Developer Experience

How quickly a developer can sign up and send a first message.

FieldPreludeSmstools
Self-service onboardingYesYes
Free developer creditNoFree test credit on sign-up
Docs qualityhighhigh
DocumentationOpen ↗Open ↗
SDKsNode.js, Python, Go, Java, Ruby, PHP, C#PHP, Node.js, Python, Ruby, PowerShell
Sandbox / test envNoYes
API typesRESTREST, SMTP
What's the differenceOn SDKs, Prelude adds Go, Java, C#; Smstools adds PowerShell; Smstools offers Sandbox / test env, while Prelude does not; on API types, Smstools adds SMTP.

Data & Compliance

Data residency options and enterprise compliance certifications.

FieldPreludeSmstools
EU data residencyYesYes
US data residencyNoNo
Choose regionNoNo
GDPRYesYes
ISO 27001YesNo
SOC 2YesNo
HIPAANoNo
What's the differencePrelude offers ISO 27001, while Smstools does not; Prelude offers SOC 2, while Smstools does not.

Data Retention

How long message content and metadata are stored, and whether that is configurable.

FieldPreludeSmstools
Retention policyNot 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.Not publicly documented in detail. Smstools states all data is stored on servers located in Europe under GDPR-compliant processes, with AES-256 encryption at rest and TLS 1.3 in transit, and a Data Processing Agreement is available on request, but no specific message content/metadata retention periods are published.
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. Smstools: Not publicly documented in detail. Smstools states all data is stored on servers located in Europe under GDPR-compliant processes, with AES-256 encryption at rest and TLS 1.3 in transit, and a Data Processing Agreement is available on request, but no specific message content/metadata retention periods are published.

Pricing & Credits

Pricing model and the cost of a first message.

FieldPreludeSmstools
Pricing modelPay-as-you-go per-verification pricing plus at-cost (zero-markup) per-message charges, with optional Startup subscription and custom Enterprise tiers.Pay-as-you-go per message with volume discounts; no subscription, setup fee or monthly minimum, with a personalised rate sheet issued on registration.
SMS starting price€0.0043 per SMS (US, at-cost); verification fee from €0.032From €0.025 per SMS to the USA (rates vary by destination country and volume)
Free developer creditNoFree test credit on sign-up
What's the differencePrelude and Smstools are closely matched on pricing & credits — no material differences in the tracked fields.

Reach & Reliability

Global coverage and delivery dependability.

FieldPreludeSmstools
Countries covered230200
Direct operator connectionsYesYes
Published uptime SLANo published SLA99.99% (uptime SLA)
What's the differencePrelude leads on Countries covered (230 vs 200 for Smstools).

Company & Trust

Independent reviews and company profile.

FieldPreludeSmstools
G2 rating4.90.0
G2 reviews130
Ownershipprivateprivate
Employees51-2001-10
What's the differencePrelude leads on G2 rating (4.9 vs 0 for Smstools); Prelude leads on G2 reviews (13 vs 0 for Smstools).

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