Support
Help, from the people who built it.
Most answers are below. If yours isn't, write — a person reads every message.
Write to us at support@ninjacompress.app.
If something went wrong, the fastest fix starts with Settings → Diagnostics → Export diagnostics (and, if the app hit an error, Export error log). Ninja keeps its own engine log on your phone — it never sends it anywhere — and exporting shares that text once, into the app you pick. Attach it to your email and we can usually see exactly which step failed.
Common questions
A compression failed. What happened?
When a phone's hardware encoder refuses a file, Ninja steps down a four-rung fallback ladder and finishes in software rather than failing. If a job still fails, nothing is deleted — the original is exactly where it was. Settings → Diagnostics shows which engine ran and why a step failed, and you can export that text to us.
Why did my queue pause?
If your phone gets hot, Ninja pauses the queue between files and says so in the notification. It carries on once the phone has cooled. You can also pause by hand, from the notification or in the app — Ninja finishes the video it's on, then stops.
Where did my original go?
Wherever you told it to. Keep both leaves it untouched. Ninja Vault moves it to the in-app Vault, where you can restore it until you empty it. Move to system Trash and Replace original both send it to your phone's Trash — Recently Deleted in Photos on iPhone — restorable for 30 days. Only Delete permanently, on Android, removes it outright; the iPhone app doesn't offer it.
Can Ninja replace an original with a worse file?
No. An original is only touched after the compressed copy passes nine checks — including that it plays from start to end, that its audio survived, and that it is actually smaller. One failed check and the original stays.
Why is Reverse limited to one minute?
Reversing means holding every frame in memory at once. Past about a minute, phones run out — so Ninja refuses rather than crashing halfway through.
Does Ninja need an internet connection?
Not to compress, convert or edit — it works identically in airplane mode, and the Android app doesn't even request the Internet permission. Buying or restoring Ninja Pro goes through the Google Play or App Store app, which needs a connection; after that, Pro works offline.
Which languages does it speak?
English, Arabic, Catalan, Chinese (Simplified), Chinese (Traditional), Croatian, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Thai, Turkish, Ukrainian and Vietnamese.
How do I remove everything Ninja stored?
Clear the app's data in Android Settings, or uninstall it. On iOS, delete the app. That removes its history, Vault, presets and settings. Videos you saved to your gallery stay — they're yours.
Ninja Pro: restore, cancel, refund
Ninja Pro is bought through Google Play or the App Store, and there's no Ninja account. Your store account is the record of what you own.
How do I get Pro back on a new phone, or after reinstalling?
Sign in with the same Google Play or Apple account, open Ninja's Pro screen and tap Restore purchases. A Google Play purchase doesn't carry over to the App Store, or the other way round.
I paid, but Pro isn't unlocked.
Connect to the Internet, open the Pro screen and tap Restore purchases, so the store app can confirm the purchase. After that, Pro keeps working offline. If it still doesn't unlock, write to us with the date of purchase — never your card details.
How do I cancel a subscription?
On Android: Google Play → your profile → Payments & subscriptions → Subscriptions. On iPhone: Settings → your name → Subscriptions. Deleting Ninja doesn't cancel it. Pro stays on until the end of the period you've paid for. Lifetime is a one-time purchase, so there's nothing to cancel.
How do I get a refund?
Refunds are decided by the store you paid, under its own policy. For the App Store, use reportaproblem.apple.com. For Google Play, follow Google's refund steps. Apple handles every App Store refund itself. If Google Play sends you to the developer, email us with the order number from your Google Play receipt (it starts with GPA). The terms cover renewal and refunds in full.
Still stuck?
Email support@ninjacompress.app with your phone model, the app version from the Settings screen, and — if you can — the exported diagnostics. The guides cover the bigger questions: which codec to pick, how platform size limits work, and how to get a long video under a cap.