OpenAI API vs OneSignal
Frontier models: GPT-5, o-series reasoning, image, audio, embeddings
vs. Mobile + web push, email, SMS, and in-app messaging at consumer scale
Pricing tiers
OpenAI API
Free Tier (Trial)
$5 free credit for new accounts. Rate-limited.
Free
Pay-as-you-go
No monthly min. Per-token pricing by model.
$0 base (usage-based)
Usage Tiers (1-5)
Automatic tier promotion based on cumulative spend. Higher tiers = higher rate limits + new model access.
$0 base (usage-based)
Enterprise
Custom. Priority access, SLA, dedicated capacity.
Custom
OneSignal
Free
Unlimited mobile push, 10K web push subs, 10K email/mo, 1 journey. GDPR compliant.
Free
Growth
$19/mo + usage. 20K email/mo included, then $1.50/1K. 3 journeys. Advanced in-app.
$19/mo
Professional
Custom. Unlimited volume, 20 journeys, CSV export, prioritized support.
Custom
Enterprise
Custom. Dedicated CSM, SLA, frequency capping, advanced permissions, HIPAA options.
Custom
Free-tier quotas head-to-head
Comparing free-tier on OpenAI API vs free on OneSignal.
| Metric | OpenAI API | OneSignal |
|---|---|---|
| active journeys | — | 1 journeys |
| email monthly | — | 10000 emails/mo |
| mobile push | — | Unlimited subscribers |
| web push subscribers | — | 10000 subscribers |
Features
OpenAI API · 12 features
- Assistants API — Stateful assistants with tools, threads, file search.
- Batch API — 50% discount for async processing within 24h.
- Chat Completions API — Classic /v1/chat/completions endpoint.
- Files API — Upload docs for retrieval, fine-tuning, batch.
- Fine-Tuning — Supervised + DPO fine-tuning for GPT-4o, GPT-4.1, GPT-4o-mini.
- Function Calling — JSON-schema tool calling; parallel calls supported.
- Moderation — Safety classifier API (free).
- Prompt Caching — Auto-cache repeated prefixes; 50% cheaper cached hits.
- Realtime API — WebSocket streaming voice + text with low latency.
- Responses API — Stateful conversational API.
- Structured Outputs — Enforced JSON schema compliance.
- Vision — Image input for GPT models.
OneSignal · 12 features
- A/B Testing — Split testing across push, email, in-app.
- Analytics + Cohorts — Delivery, open, click, conversion metrics + retention cohorts.
- Email — Transactional + marketing email with templates.
- Frequency Capping — Limit message frequency per user.
- In-App Messaging — In-app banners, modals, surveys, carousels triggered by events.
- Intelligent Delivery — Optimize send time per user with ML.
- Journeys — Multi-step automations with branching, delays, actions.
- Live Activities — iOS Dynamic Island + Live Activities.
- Mobile Push — iOS (APNs), Android (FCM/HMS) push notifications.
- Segments — Dynamic audience targeting by tags, location, behavior.
- SMS — Two-way SMS in 200+ countries.
- Web Push — Browser push via service workers (Chrome, Firefox, Edge, Safari, Opera).
Developer interfaces
| Kind | OpenAI API | OneSignal |
|---|---|---|
| SDK | openai-dotnet, openai-go, openai-node, openai-python | OneSignal Android SDK, onesignal_flutter, OneSignal iOS SDK, @onesignal/node-onesignal, OneSignal Unity SDK, OneSignal Web SDK, react-native-onesignal |
| REST | OpenAI REST API | OneSignal REST API |
| MCP | OpenAI MCP | — |
| OTHER | Realtime API (WebSocket) | Outbound Webhooks |
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