Resize Video for Any Platform
Pick the frame you need, decide what should happen to the shape that does not fit, and export. Every platform's upload size is one click, the preview shows the real output frame with the bars in it, and the whole reframe runs on your own machine — nothing is uploaded and nothing is watermarked.
Three ways to fill a frame, and what each costs
When your video and the target frame are different shapes, something has to give. There are exactly three things that can give, and every tool that reframes video is choosing between them — most just do not tell you which one they picked.
Crop to fill
Fills the frame edge to edge. Drag the box to choose what stays in shot.
Whatever falls outside the box is gone from the export.
Fit with bars
Keeps the whole picture and fills the leftover space with black bars.
Nothing is lost, but the picture is smaller inside the frame.
Stretch to fit
Pulls the picture to the frame's shape.
Everything in shot changes shape. Faces are where this shows first.
Which one is right depends entirely on the footage. A talking head with room around it crops beautifully; a wide landscape shot loses its whole subject and wants bars instead. The tool computes the discarded percentage and the bar thickness for your actual clip, so the choice is made with the numbers rather than after the export.
Platform upload frames
| Placement | Frame | Ratio | Notes |
|---|---|---|---|
| Instagram Reels and Stories | 1080 × 1920 | 9:16 | Keep text away from the top and bottom 250 px for the UI overlay. |
| TikTok | 1080 × 1920 | 9:16 | Same safe-area caution: captions and buttons sit over the edges. |
| YouTube Shorts | 1080 × 1920 | 9:16 | Anything squarer than 9:16 gets pillarboxed in the Shorts feed. |
| Instagram feed | 1080 × 1350 | 4:5 | Tallest ratio the feed shows without cropping. |
| Instagram square | 1080 × 1080 | 1:1 | The safe third option: it reads the same in the feed and the grid. |
| LinkedIn feed video | 1080 × 1080 | 1:1 | Square wins more feed height on mobile. |
| YouTube (landscape) | 1920 × 1080 | 16:9 | Upload up to 3840 × 2160 for a 4K option on the player. |
| Facebook feed video | 1080 × 1350 | 4:5 | Square is the safer choice for mixed desktop and mobile viewing. |
| X / Twitter | 1280 × 720 | 16:9 | Portrait plays too, but the timeline crops the preview. |
These are the same records the aspect ratio calculator publishes and the same ones the buttons above fill in, so a frame quoted here is the frame the tool writes. The ratio column is derived from the pixel dimensions rather than typed alongside them, which is why it cannot drift out of step with them.
Why this is fast but not instant
Some video edits are free. Trimming the end off a clip can be a straight copy of the compressed data, and removing an audio track barely touches the file at all. Changing the shape of the picture is not one of those edits: every frame has to be decoded, cropped or padded, scaled and encoded again, and there is no shortcut around it in any tool, local or otherwise.
What makes it quick here is where that work happens. This runs on WebCodecs, which hands the job to the same hardware video encoder your phone or laptop uses to record — not to a WebAssembly software encoder, and not to a server you have to upload to and then wait in a queue behind. For most clips the export finishes in the time it would have taken to upload the file.
Frequently asked questions
How do I resize a video for Instagram or TikTok?
Pick the placement from the list — each one carries the platform's own upload frame — then choose what should happen to the shape difference. Crop to fill puts the box under your control and fills the frame edge to edge; fit with bars keeps every pixel and pads the rest. The frame, the discarded share and the bar thickness are all shown before you run it.
What is the difference between crop, fit and stretch?
They are the three possible answers when your video and the target frame are different shapes, and each costs something. Crop fills the frame and loses whatever falls outside the box. Fit keeps the whole picture and adds black bars where its shape does not reach the edges. Stretch keeps everything and fills the frame by changing the shape of the picture, which is visible on faces first. There is no fourth option and no free one.
Will resizing make my video blurry?
Shrinking will not — a 4K clip scaled to 1080 × 1920 stays sharp. Enlarging will, because no encoder can add detail that was never recorded, and this tool tells you when the output frame is bigger than the picture going into it. If you see that warning, a smaller output frame will genuinely look better than a larger one.
Does this upload my video anywhere?
No. The reframe runs on WebCodecs, the video encoder built into your browser, so the file is read from disk, decoded, cropped, scaled and re-encoded inside this tab. There is no server, no queue and no account, and nothing is watermarked. Closing the tab removes every trace, because there was never a copy anywhere else.
Can I resize to a size that isn't in the list?
Yes — choose Custom size and type the width and height. Anything from 16 to 7680 pixels on either axis is accepted, both are rounded to even numbers because video encoders require it, and the plan updates as you type so you can see what a given frame does to your picture before committing to an export.
Is resizing the same as compressing?
No, though they are often confused because both make files smaller. Resizing changes the picture's dimensions; compressing changes how many bits per second are spent describing it. If your problem is an upload limit measured in megabytes, the compressor is the tool — it works backwards from the size you name. If your problem is a frame that is the wrong shape, this is the one.
Which formats and browsers work here?
MP4, MOV, MKV and WebM go in, up to 2 GB. Output is MP4 (H.264), or WebM (VP9) on browsers without an H.264 encoder. AVI, WMV, FLV and MPG cannot be read by the browser's built-in video engine at all — convert one to MP4 first and bring that back. Any current version of Chrome, Edge, Safari or Firefox has what this needs.