Resize Video & Add Subtitles on iPhone and Android — No App Needed

Two Common Phone Tasks — One Browser

You shot a video on your phone and need to resize it for TikTok or add captions before posting. Most people think they need a video editing app. They download a 200MB app, sit through ads, get watermarked output, and delete the app 10 minutes later.

Browser tools do both tasks without installing anything:

Task	Tool	Time
Change resolution (4K→1080p, save space)	Video Resizer	1 min
Crop to 9:16 for TikTok/Reels	Video Cropper	1 min
Add burned-in subtitles	Add Subtitles	2 min
Compress for sharing	Video Compressor	1-2 min

Resize Video on iPhone

iPhone records at 4K by default on newer models. A 1-minute 4K video is ~350MB. To shrink it:

1. Open the Video Resizer in Safari
2. Select the video from Photos
3. Choose 1080p (1920×1080) — looks identical on phone screens, 60-75% smaller
4. Download — saves to Files app

To change resolution on iPhone permanently: Settings → Camera → Record Video → select 1080p instead of 4K. This prevents large files going forward. But if you already have 4K footage, resize after the fact with the browser tool.

For TikTok/Reels: Use the Video Cropper instead — crop to 9:16 vertical, which simultaneously resizes and reframes the video.

Resize Video on Android

Same workflow, Chrome instead of Safari:

1. Open the Video Resizer in Chrome
2. Select video from your gallery
3. Choose target resolution
4. Download to your Downloads folder

Samsung tip: Samsung phones record at various resolutions depending on the mode. Check your camera settings — "High Efficiency" mode (HEVC/H.265) produces smaller files than "High Compatibility" mode (H.264). If your files are already large, resizing to 1080p in the browser is the fastest fix.

Add Subtitles on Your Phone

Adding captions before uploading to social media:

1. Open the Add Subtitles tool in your phone's browser
2. Select your video
3. Auto-generate captions or upload an SRT file
4. Review the text — fix any names or technical terms the AI got wrong
5. Adjust font size (make it larger for mobile viewers)
6. Download with subtitles burned in

Phone-specific tip: When styling subtitles for content that will be viewed on phones, use at least 24px font. What looks big on your screen looks normal to your audience — most viewers watch on the same size screen you are using to edit.

The Full Mobile Social Pipeline

From recording to posting — all on your phone:

1. Record your video (landscape or vertical)
2. Trim to the key section with the Video Trimmer
3. Add subtitles with the subtitle tool — auto-generate, review, burn in
4. Crop to 9:16 for TikTok/Reels with the Cropper
5. Compress if needed with the Compressor
6. Upload directly from your Files/Downloads folder

Total time: 5-8 minutes. No app download, no account creation, no watermarks. The browser tools run on your device — nothing is uploaded to any server.