Comparison

Overview

Company snapshot and where each provider is based.

FieldGatewayAPIPrelude
What it isDanish SMS gateway and messaging platform by ONLINECITY.IO offering SMS, RCS and email APIs with pay-as-you-go pricing and EU data hosting.Developer platform for phone and email verification (OTP), authentication, number intelligence, and anti-fraud onboarding delivered across SMS, RCS, WhatsApp, voice and other channels.
Founded19992022
Ownershipprivateprivate
Employees11-5051-200
HQ cityOdenseParis
HQ countryDenmark (EU)France (EU)
What's the differencePrelude edges ahead on the overall messaging.dev Score (62 vs 54). GatewayAPI is private and headquartered in Odense, Denmark (EU); Prelude is private and based in Paris, France (EU).

Channels

Which messaging channels each provider can send and receive on.

FieldGatewayAPIPrelude
SMSYesYes
MMSNoNo
RCSYesYes
WhatsAppNoYes
ViberNoYes
Facebook MessengerNoNo
TelegramNoYes
Apple Messages for BusinessNoNo
VoiceNoYes
EmailYesYes
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.

FieldGatewayAPIPrelude
Self-service onboardingYesYes
Free developer creditTest credits on requestNo
Docs qualitymedhigh
DocumentationOpen ↗Open ↗
SDKsNode.js, Python, Go, Java, Ruby, PHP, C#
Sandbox / test envNoNo
API typesREST, SMPP, Email-to-SMSREST
What's the differenceOn SDKs, Prelude adds Node.js, Python, Go, Java, Ruby, PHP, C#; on API types, GatewayAPI adds SMPP, Email-to-SMS.

Data & Compliance

Data residency options and enterprise compliance certifications.

FieldGatewayAPIPrelude
EU data residencyYesYes
US data residencyNoNo
Choose regionYesNo
GDPRYesYes
ISO 27001NoYes
SOC 2NoYes
HIPAANoNo
What's the differenceGatewayAPI offers Choose region, while Prelude does not; Prelude offers ISO 27001, while GatewayAPI does not; Prelude offers SOC 2, while GatewayAPI does not.

Data Retention

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

FieldGatewayAPIPrelude
Retention policyMessage content, sender and recipient are stored in the traffic log for 30 days, after which records are anonymized (message content and full sender deleted, last half of the recipient number removed). An optional "secret" message class skips storage of content, sender and recipient entirely.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.
What's the differenceGatewayAPI: Message content, sender and recipient are stored in the traffic log for 30 days, after which records are anonymized (message content and full sender deleted, last half of the recipient number removed). An optional "secret" message class skips storage of content, sender and recipient entirely. Prelude: 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.

Pricing & Credits

Pricing model and the cost of a first message.

FieldGatewayAPIPrelude
Pricing modelPay-as-you-go per-message pricing with prepaid credit; no monthly subscriptions or fees (except short-code countries), with negotiated discounts for high volumes.Pay-as-you-go per-verification pricing plus at-cost (zero-markup) per-message charges, with optional Startup subscription and custom Enterprise tiers.
SMS starting priceFrom €0.0061 per SMS (standard class, cheapest destination on the public price list; e.g. €0.0401 to Denmark)€0.0043 per SMS (US, at-cost); verification fee from €0.032
Free developer creditTest credits on requestNo
What's the differenceGatewayAPI and Prelude are closely matched on pricing & credits — no material differences in the tracked fields.

Reach & Reliability

Global coverage and delivery dependability.

FieldGatewayAPIPrelude
Countries covered200230
Direct operator connectionsYesYes
Published uptime SLANo published SLA (99.99%+ historical uptime claimed)No published SLA
What's the differencePrelude leads on Countries covered (230 vs 200 for GatewayAPI).

Company & Trust

Independent reviews and company profile.

FieldGatewayAPIPrelude
G2 rating4.94.9
G2 reviews713
Ownershipprivateprivate
Employees11-5051-200
What's the differencePrelude leads on G2 reviews (13 vs 7 for GatewayAPI).

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