Messaging App Testing Checklist (End-to-End, 2026)

Messaging apps fail on three things: delivery, ordering, and privacy. Everything else is polish. Users expect messages delivered reliably, in order, and secure. This checklist covers the test surfaces

Messaging apps fail on three things: delivery, ordering, and privacy. Everything else is polish. Users expect messages delivered reliably, in order, and secure. This checklist covers the test surfaces that matter.

Delivery

1. Send message — delivered within 2 seconds on good network
2. Offline message queues locally
3. Queued message delivers on reconnect
4. Duplicate send prevented (no double messages)
5. Large group message (100+ recipients) delivers reliably
6. Attachment (image, video, voice) delivers with progress visible

Ordering

1. Messages arrive in send order
2. Late-arriving message inserts at correct timestamp
3. Clock skew between sender / receiver does not cause out-of-order
4. Read receipts respect timeline

Receipts / presence

1. "Sent" status visible
2. "Delivered" status accurate
3. "Read" status accurate and optional-on per privacy setting
4. Typing indicator appears and disappears correctly
5. Online / last-seen respects privacy setting

Media

1. Image send works; thumbnail generated
2. Video send with compression or quality option
3. Voice note record and send
4. File attachment (PDF, docs)
5. Download media on receive (auto or manual per preference)
6. Media expiration / disappearing messages work per design

Group

1. Create group, invite members
2. Member list accurate, role-based
3. Admin controls (kick, promote, name change) functional
4. Group name / image edits propagate
5. Leave group works
6. Deleted group handled for remaining members

Security and privacy

1. End-to-end encryption (E2EE) in transit — verified via keys
2. Key verification (scan QR) works
3. Key change warning shown when contact re-installs
4. Disappearing messages actually disappear server-side
5. Delete for me vs delete for everyone behaves correctly
6. Block user — severs all communication
7. Reports reach moderation

Search

1. Message search finds text across conversations
2. Search within chat
3. Media search (only photos, only videos)
4. Link / file search

Backup / restore

1. Chat backup flow works (cloud or local)
2. Restore on new device restores chats
3. Restore preserves media
4. Backup encrypted

Notifications

1. Push delivers within 5 seconds of server receipt
2. Notification shows sender + preview (per privacy setting)
3. Badge count accurate
4. Notification action (quick reply) works
5. Quiet hours respected
6. Grouped notifications per conversation

Voice / video calling

1. Incoming call rings
2. Outgoing call connects within 5 seconds
3. Audio / video quality acceptable on 4G
4. Mute / video toggle work
5. Call ends cleanly
6. Missed call logged
7. Group call for 3+ participants functional

Account

1. Sign up with phone / email
2. OTP verification works
3. Contact sync (if enabled) respects privacy
4. Display name / photo update syncs
5. Deactivate account option available

Accessibility

1. Screen reader reads incoming messages
2. Typing indicator announced
3. Call accessible via assistive tech
4. Large text supported in conversations
5. Alt text on sent images (if supported)

Performance

1. Scrolling message history smooth
2. Cold start < 2s
3. Memory stable over long conversations
4. Battery drain reasonable for foreground
5. Background sync efficient

Edge cases

1. Very long message (10k chars) — truncated or handled
2. Special characters, emoji, unicode preserved
3. RTL language (Arabic, Hebrew) renders correctly
4. App backgrounded mid-send — delivery still completes
5. Force-close mid-call — reconnects or cleanly fails
6. Two devices logged in — both receive, read sync cross-device
7. Timezone change between devices — messages still chronological

How SUSA tests messaging

adversarial persona tests block, report, unusual inputs. accessibility_user verifies screen reader on message stream. impatient times message send-receive latency.

susatest-agent test chat.apk --persona adversarial --steps 200

Common bugs

• Messages out of order when sent rapidly over unstable network
• Read receipt fires on notification preview (user did not actually open)
• Disappearing messages not disappearing from backup
• Voice call drops on network switch (Wi-Fi → cellular)
• Block user still lets recipient see typing indicator

Messaging is deeply tested by users. Ship with confidence or do not ship.