Add a blurred background to a video
When you turn a horizontal video vertical, two-thirds of the 9:16 frame is empty. You can leave it black — or you can fill it with a blurred, enlarged copy of the video itself. The clip plays sharp in the middle; behind it, the same footage runs soft and dim, edge to edge. It's the look every polished Reel and TikTok repost uses, and it takes one click here.
No crop, so you keep the whole frame. No black bars, so it looks made for vertical. Below: what it is, exactly how it's built, and when it beats the alternatives.
First video free, no signup · MP4, MOV, MKV, WEBM, AVI
Updated 24 July 2026 · by Yohann Kipfer, who writes the encoder behind make-vertical.com
What a blurred background actually is
A 16:9 video is 1.78× wider than it is tall. Drop it into a 9:16 canvas at full width and it occupies a centre band 1080 × 608 px high — 31.6% of the 1920-px height. The other 68.4% has to be something. A blurred background makes that something a scaled-up, heavily blurred copy of the same clip, so the screen is full and the colours behind your subject move with the footage instead of sitting as two black slabs.
Creators reach for it for three concrete reasons: it fills the frame so the video looks native to a vertical feed; it keeps 100% of the original picture (a crop throws away 68.4%); and it avoids the “reposted” signal that black bars send — feeds tend to favour content that looks built for them.
How it's built, in one pass
No layers to stack by hand. The encoder splits your clip into two copies and composites them:
- 1Background copy
Scaled up to cover the whole 1080 × 1920 canvas (so no gaps), then blurred and darkened slightly so it never fights the foreground for attention.
- 2Foreground copy
Scaled to fit inside the frame at full sharpness — 1080 × 608 for a 16:9 source — and overlaid dead-centre on top of the blur.
For the curious, that's literally the ffmpeg graph this tool runs — the same fragment lives in worker/ffmpeg.ts:
[0:v]split=2[fg][bg];
[bg]scale=W/4:H/4:force_original_aspect_ratio=increase,
crop=W/4:H/4,boxblur=8:2,scale=1080:1920,
eq=brightness=-0.06[bgb];
[fg]scale=1080:1920:force_original_aspect_ratio=decrease[fgs];
[bgb][fgs]overlay=(W-w)/2:(H-h)/2- boxblur=8:2. Radius 8, two passes — enough that no shape in the background is legible, which is the point: a readable background pulls the eye off your subject.
- Blurred at quarter resolution. The background is scaled down to 270 × 480 before the blur, then scaled back up. Blurring a soft image you're about to enlarge looks identical to blurring the full frame, and it's several times cheaper to compute — which is why the export is quick rather than a two-minute render.
- eq=brightness=-0.06. A slight darkening of the background so the sharp foreground reads as the subject. Small number, real difference.
- force_original_aspect_ratio: increase vs decrease. The background increases to cover (then is cropped); the foreground decreases to fit (never cropped). Same clip, opposite scaling — that's the whole trick.
Blurred background vs black bars vs solid colour
All three fill the same empty 68.4% and all three keep your whole frame. They differ on how the result reads and how big the file is.
| Fill | Look | File size | Readability |
|---|---|---|---|
| Blurred backgrounddefault | Native vertical. The eye reads the fill as depth, not as empty space. | Largest — the blur is moving detail, so H.264 spends real bits on it. | Best. Nothing competes with the foreground; the blur is dim and out of focus. |
| Black bars | Reads as 'reposted from a horizontal source'. Two dead bands. | Smallest — flat black compresses to almost nothing. | Fine, but the bands look like wasted screen unless you put captions in them. |
| Solid colour | Cleaner than black, still obviously a fill. Works if it matches your brand. | Tiny — a flat colour compresses like black bars. | Good, provided the colour contrasts with your video edges. |
The honest trade: the blurred background is the only one that costs extra megabytes, because it's the only fill that isn't flat. At CRF 21 the difference is a handful of megabytes on a short clip — worth it for how much more finished it looks. If you need the smallest possible file and plan to caption the dead space, black bars win.
When a blurred background is the right call
The rule of thumb: use it whenever cropping would cut something that matters. Four cases where it nearly always does:
The classic. Cropping a centred presenter to 9:16 works, but the moment they gesture or lean, a static crop cuts them off. A blurred background keeps the whole shot and never clips a hand mid-sentence.
Two guests sitting 1.2 m apart don't fit in a 608-px crop — one always falls out. Keep the full 16:9 and blur behind it, and both stay in frame the whole clip.
A game HUD lives at the edges: minimap, health, ammo. Crop to vertical and you cut the information the clip is about. The blurred background keeps the full HUD readable.
Slides and screen recordings are unreadable once cropped to a third of their width. Fit the whole thing in at 1080 × 608 with a blurred fill and the text survives.
The one time to skip it: a single subject you want to fill the whole screen — a dance clip, a sport highlight — where the sides really are disposable. Then crop, ideally with subject tracking so the frame follows the action.
Add your blurred background
Online, no software. Upload a clip, choose the blurred-background fill, export at 1080 × 1920. First video free.
MP4, MOV, MKV, WEBM, AVI in · 1080 × 1920 MP4 out
Frequently asked questions
How do I add a blurred background to a video for free?
Upload a clip here, pick the blurred-background fill, export. The first video is free (it carries a small watermark). No software to install and nothing to configure — the blur, the scaling and the centring are all automatic.
Does the blurred background reduce my video's quality?
No — your actual video is untouched. It's placed at 1080 × 608 inside the 1080 × 1920 canvas at full resolution. Only the background copy is blurred, and it's meant to be blurred. Because nothing is cropped, there's no upscaling either, so this often looks sharper than a crop-to-fill.
What resolution does it export?
1080 × 1920 (or 720 × 1280 if you choose it). H.264, yuv420p, so every phone and platform plays it directly. The foreground keeps its original detail; the background is blurred on purpose.
Is this the same as blurring faces or blurring part of a video?
No — and this trips people up. This blurs a background copy of the clip to fill a vertical frame; the main video stays sharp. If you want to blur a face, a licence plate or a region for privacy, that's a different job handled by our sister tool make-blur.com. This page is only about the fill-the-frame background.
Which formats does it accept?
MP4, MOV, MKV, WEBM and AVI in; MP4 out. Any aspect ratio works as input — 16:9 is the common one, but a 4:3 or square clip gets the same treatment.
Keep going
Fill the frame, keep the footage.
Upload a horizontal clip and get a 1080 × 1920 with your own video, blurred, behind it.
Add a blurred backgroundFirst one free · see pricing