You export a clean, crisp caption PNG, drop it onto your clip — and it looks soft, almost pixelated, once you actually watch the video back. Or the opposite happens: the caption that looked perfectly sized in the export preview shows up tiny in the corner of your video. Both problems come from the same root cause, and it's a one-setting fix.
The cause: a canvas-size mismatch
A transparent caption PNG is exported at a specific pixel width — its "canvas." Your video is also a specific pixel width — its resolution. When these two don't match, your video editor has to scale the image to fit, and scaling is where the trouble starts.
- Canvas smaller than the video: the editor stretches the PNG up to fill the frame, and stretching a smaller image larger makes it visibly soft or blurry — the same reason a small photo looks bad blown up to fill a screen.
- Canvas larger than the video: the editor shrinks the PNG down, and your caption ends up smaller on screen than you designed it to look.
Neither is a bug in your editor — it's simply doing what scaling always does. The fix is to never need to scale in the first place.
The fix: match canvas width to your video resolution
Most vertical short-form video — Shorts, Reels, TikTok — exports at 1080 pixels wide. If your caption tool lets you choose a fixed canvas width, set it to 1080px to match exactly. If you're working with a higher-resolution vertical export, use 1920px instead. Either way, the goal is the same: export width equals video width, so the caption drops in at 1:1 scale with no stretching in either direction.
| Video type | Typical resolution (width) | Caption canvas to use |
|---|---|---|
| Standard Shorts / Reels / TikTok | 1080px | 1080px |
| Higher-res vertical export | 1920px | 1920px |
| Older / smaller vertical export | 720px | 720px |
Magic Subtitle Exporter lets you pick a fixed canvas width (720 / 1080 / 1920px) before exporting, so you can match it to whatever resolution your video editor is set to export at.
→ Export sharp caption PNGs with the free Magic Subtitle Exporter — runs in your browser, nothing is uploaded.Step-by-step
- Check your video's export resolution in your editor's export settings — this is your target width.
- Open Magic Subtitle Exporter and set the canvas width to match that same number.
- Design your caption — font, size, color, outline — and export the PNG.
- Drop it onto your clip at 100% scale, no resizing. It should now line up crisp and at the intended size.
Still slightly off? Check one more thing
If the width matches and it's still not quite right, double-check that your editor isn't auto-scaling the image layer by default (some apps fit imported images to a preset frame automatically). Look for a "100%" or "actual size" option on the image layer before you adjust anything else.
Frequently asked questions
Why does my caption look blurry once it's on my video?
Almost always because the exported PNG's canvas width is smaller than your video's resolution. When your editor stretches a smaller image up to fill a larger frame, it gets visibly soft.
What canvas width should I use?
Match it to your video's export resolution: 1080px wide for standard vertical Shorts/Reels/TikTok, or 1920px if you're exporting a higher-resolution vertical video.
Why is my caption too small on the video instead of blurry?
That happens when the canvas is larger than your video resolution — the editor shrinks the image down, and your text ends up smaller than intended. Match the canvas width to the video resolution to avoid both problems.
Is it free?
Yes — no account, no upload, no watermark.
Setting up a caption style for the first time? Our guide to reusing your caption style across every video covers building it once and exporting it everywhere.
Caption looking soft on your finished video? Re-export it at the matching canvas width with Magic Subtitle Exporter and it'll drop in crisp.