Every platform wants something different: vertical 9:16 for TikTok and Reels, 4:5 for the Instagram feed, wide for X, small for email. Tell ToolGPT where the video is going and it prepares a copy with the right frame, size and length — without cropping anything out of your picture.
Open ToolGPT and press the + button beside the message box, or drop the file into the chat. No account is needed to start.
Say where it's going. ToolGPT opens a recipe card showing the target frame, background and the part of the video that will be kept, which you can adjust.
Press Apply (or ask the assistant to). The result is an MP4 in the platform's shape, ready to post.
ToolGPT has a recipe for each common destination. TikTok, Instagram Reels, YouTube Shorts and WhatsApp Status get a vertical 1080×1920 (9:16) video. The Instagram feed gets 1080×1350 (4:5), X/Twitter gets 1280×720 (16:9), and Email gets a small 960×540 copy that is easier to attach.
Every recipe produces an H.264 MP4 with AAC audio, which all of these platforms accept, and keeps your video's own frame rate unless it is higher than the recipe allows.
Turning a landscape video into a vertical one usually means losing the sides of the picture. The recipe does the opposite: the whole picture is fitted into the new frame, and the empty space is filled with a blurred copy of the video — or black, white or a colour of your choice. People and text at the edges stay visible.
If you only want a shape — "make it square", "make it 16:9" — without the platform's size and length rules, ask for that instead; ToolGPT will show you the aspect options on your own frame.
Each recipe has a length limit: 60 seconds for TikTok, Shorts, the Instagram feed and Email, 90 seconds for Reels, 30 seconds for WhatsApp Status and 140 seconds for X. When a video is longer, the card keeps the first stretch by default, and you can drag the range to the part you want — or just say "use the bit from 0:20".
The whole job runs in your browser with a WebAssembly build of FFmpeg, so your video is not uploaded to prepare it.
No. The whole picture is fitted into the platform's frame and the rest is filled with a blurred background or a colour you choose.
No. It prepares the file; you download it and upload it to the platform yourself.
No. The recipe runs in your browser.
Try it with your own file
Open ToolGPT, attach a file, and type what you want done.