On your phone
Caption a video on your phone, without an app store.
Open it in your browser, add it to the home screen if you want it there. Nothing to install, and no upload over mobile data.
LumaCaption runs in a phone browser on Android and iPhone and can be added to the home screen, so captioning a video needs no app-store download — and because the video file is never uploaded, a large clip does not have to travel over mobile data.
Captioning on a phone usually means one of two bad options: install an app that wants storage, contacts and a subscription before it will show you anything, or upload a 200 MB clip over mobile data to a website and wait.
Neither is necessary. This runs in the phone browser, and can be added to your home screen so it opens like an app if that is how you want it. More importantly, the video file is never uploaded — which on a phone is not only a privacy point but a bandwidth one: nothing has to travel over your data connection for captions to appear.
No app-store download
Open it in Chrome or Safari and start. Add it to the home screen if you want an icon; nothing about that step is required.
No large upload over mobile data
Your video file never leaves the phone, so a long clip does not have to be sent anywhere before captioning can begin.
Built for one thumb
The timeline, style picker and transcript are designed for phone use — select then drag, inset trim handles, tap to split at the playhead.
The full catalogue on mobile
All 240+ styles, all 69 caption faces, the transcript editor and per-word colour are the same on a phone as on a laptop.
What actually works well on a phone — and what does not
Honesty is more useful here than a feature list. Transcribing, correcting the transcript, picking a style, dragging the captions and exporting a short clip are all comfortable on a phone. That covers the great majority of short-form work.
What is harder on a phone is anything long. A 60-minute episode is a large amount of processing for a device that is also running your messages, and phone browsers are aggressive about reclaiming memory from heavy background work. For long-form, a laptop is the right tool and this is not a limitation the interface can design around.
The other phone-specific thing worth knowing: leave the tab in the foreground while a long transcription runs. Mobile browsers suspend heavy work in background tabs, and a suspended job looks exactly like a stuck one.
- Comfortable on a phone
- Short clips, Status and Reels lengths, transcript corrections, style browsing, per-word colour, export.
- Better on a laptop
- Full podcast episodes, long interviews, anything over about twenty minutes.
- Keep the tab in front
- Phone browsers suspend heavy work in background tabs. Long transcription needs the tab visible.
- Add to home screen
- Optional. It gives you an icon and a full-screen window; everything works the same either way.
Captioning where the video was shot
The reason phone captioning matters is not convenience, it is proximity. Most short-form video is shot on the phone it will be posted from, and every step that moves the file off that phone — into a cloud drive, onto a laptop, up to a service — is a step where the workflow breaks down.
Because nothing is uploaded, the clip you just recorded can be captioned and posted from the same device in one sitting, on a train or in a shop, without waiting on a connection good enough to move a few hundred megabytes.
How it works
Open it in your phone browser
Android or iPhone. Add it to the home screen if you want an icon — nothing depends on that.
Pick the clip from your camera roll
It stays on the phone. Only the audio is used to work out the words and their timings.
Style, place and export
Drag the captions where you want them, pick from 240+ styles, export and post from the same device.
Common questions
Do I need to install an app?
No. It runs in the phone browser on Android and iPhone. You can add it to your home screen so it opens full-screen with its own icon, but that is optional and nothing works differently either way.
Does captioning a video use my mobile data?
The video file is never uploaded, so the clip itself does not travel over your connection. That is the difference between this and a website that needs a few hundred megabytes sent before it can start.
Can I caption a long video on a phone?
You can, but a laptop is the better tool past about twenty minutes. Long transcription is heavy work for a device that is also running everything else, and phone browsers suspend heavy jobs in background tabs — so if you do run one, leave the tab in the foreground.
Is the mobile version cut down?
No. All 240+ styles, all 69 caption faces, the transcript editor, per-word colour and placement are the same on a phone as on a desktop. The timeline and panels are laid out for touch rather than being a shrunken desktop UI.
Does it work on iPhone?
Yes, in Safari, and it can be added to the home screen from the share sheet. Android works the same way in Chrome.
