Tutorials
Resize Video for TikTok, Shorts, and Instagram
Use platform presets to fit social aspect ratios without leaving your browser.
Every platform crops and scales uploads differently. Posting a horizontal 16:9 clip to TikTok or Shorts without reframing leaves black bars or awkward crops. Social Media Resize applies one-click presets for TikTok, YouTube Shorts, Instagram Reels, and dozens more — processed directly in your browser.
When to resize for social platforms
Resize before you post when you:
- Repurpose a YouTube video for vertical Shorts or Reels
- Need exact pixel dimensions required by an ads manager
- Want blurred letterboxing instead of black bars for mixed aspect ratios
Resize handles frame dimensions and aspect ratio, not file size. Follow with Compress Video if upload limits still bite.
Step-by-step: resize with platform presets
- Open Social Media Resize and pick a platform preset (TikTok, YouTube Shorts, Instagram Reels, LinkedIn, etc.) or choose Custom size.
- Upload your video. The target resolution and frame rate display before you start.
- Toggle Blurred background if you want short-form-style letterboxing instead of black bars when aspect ratios differ.
- For custom targets, enter width, height, and FPS within supported ranges (16–7680 px, 1–120 fps).
- Click Resize & Download and save the MP4 output.
Encoding happens in the browser — no watermark and no remote queue.
Preset groups explained
ALTools organizes presets by platform: TikTok, YouTube, Instagram, Facebook, X, LinkedIn, Pinterest, Snapchat, Twitch, Bilibili, Douyin, and more, plus General ratios (1:1, 4:5, 9:16, 16:9).
Search the preset list if you know the aspect ratio but not the brand name.
Blurred letterbox vs black bars
| Option | Look | Best for |
|---|---|---|
| Blurred background | Fills side areas with a blurred copy of the video | Short-form feeds mimicking native apps |
| Black bars (blur off) | Traditional letterboxing | Presentations or when blur feels distracting |
Neither option invents off-screen detail — they reframe or pad what you already shot. For important on-screen text, Crop Video manually first.
One master, many exports
Creators often start from a single 16:9 YouTube master and derive vertical Shorts, square feed clips, and LinkedIn-friendly 1:1 cuts. A practical pipeline:
- Crop Video or compose vertical-safe framing on the master when possible
- Run Social Media Resize per destination preset (Shorts 9:16, Reels, TikTok)
- Compress Video only after dimensions are final
Bilibili and Douyin presets mirror domestic short-video specs — use them when cross-posting Mandarin content with the same safe zones as global apps.
Batch exports in one sitting while the source tab is still loaded; reopening a 4K master repeatedly costs time.
Ads managers sometimes reject odd dimensions — custom size is there when presets do not match a placement spec sheet exactly.
Tips for better social exports
- Shoot vertical when possible for TikTok/Reels — upscaling horizontal footage cannot recover cropped faces.
- Check safe zones — UI chrome covers edges on mobile feeds; keep titles away from the bottom third.
- Match FPS to platform — 30 fps is safe everywhere; 60 fps only when the platform rewards motion clarity.
- Compress after resize — dimension changes re-encode video; a second pass with Compress Video can hit platform size caps.
Common issues
Invalid dimensions error. Width, height, or FPS is outside allowed bounds — adjust custom values.
Subject looks tiny. Source is ultra-wide; crop with Crop Video before resizing, or use a tighter preset.
Processing fails on 4K sources. Close other tabs or trim length with Trim Video first.
Frequently asked questions
Does resize reduce file size?
Not necessarily — it changes resolution and encoding. Use Compress Video afterward if needed.
Can I use custom sizes?
Yes — pick Custom size and set width, height, and frame rate manually.
Related tools
- Crop Video — manual reframing before preset resize
- Compress Video — shrink file size for upload limits
- Video to MP4 — ensure Fast-Start web-ready output