What does an APNs payload need?

A top-level aps dictionary. To show an alert it should include an alert (with a title or body), a badge, a sound, or content-available for a silent push.

What does an FCM payload need?

A notification and/or data field. In the HTTP v1 API these sit inside a top-level message object.

Does it send the notification?

No. It only validates the JSON structure. It never sends anything, so payloads with tokens stay on your device.

Developer Tools

Push Notification Payload Validator

Validate FCM (Android) and APNs (iOS) push notification JSON payloads.

Free browser toolRuns in your browserNo sign-up

Mobile notification diagnostics

Validate FCM and APNs payload structure before delivery

Catch malformed JSON, missing platform roots and common payload-shape problems locally before sending a request to a push provider.

Android FCM

platform

errors

warnings

Notification payload

132 bytes

Notification payload (JSON)

Validation report

Structurally valid

Payload structure looks valid.

This validates JSON shape and common platform fields. It does not contact FCM/APNs, authenticate credentials, enforce every provider limit or guarantee delivery.

Private by design. Input is processed inside this browser tab and is not sent to ToolsOnDuty.

About the Push Notification Payload Validator

Push notifications are sent as JSON payloads with a specific structure. A missing key like aps or message often causes silent failures.

This tool validates the shape of Firebase Cloud Messaging (FCM) and Apple Push Notification service (APNs) payloads, pointing out errors and common warnings.

It checks structure, not delivery, and runs entirely in your browser.

Key features

FCM (Android) and APNs (iOS) modes
Checks required keys like aps and message
Warns about missing title or body
Local, private validation

How to use

1Choose FCM or APNs.
2Paste your JSON payload.
3Read the validation result, errors and warnings.

Examples

APNs alert

Input: { "aps": { "alert": { "title": "Hi" } } }

Output: Payload structure looks valid.

The required aps dictionary with an alert title passes validation.

Frequently asked questions

What does an APNs payload need?: A top-level aps dictionary. To show an alert it should include an alert (with a title or body), a badge, a sound, or content-available for a silent push.
What does an FCM payload need?: A notification and/or data field. In the HTTP v1 API these sit inside a top-level message object.
Does it send the notification?: No. It only validates the JSON structure. It never sends anything, so payloads with tokens stay on your device.

Open a related tool to prepare your files or refine the finished result.