Open Kuro

Free video tools

For the short you're about to post. Everything runs in your browser, so nothing is uploaded and nothing waits in a queue.

Your file never leaves this device. Everything runs in your browser.

Video tools

Resize a video

Turn a video into 9:16 for TikTok, Reels and Shorts, or 4:5, 1:1 or 16:9.

Crop a video

Cut a video down to the part you want to keep, at its own size.

Safe-zone checker

See where TikTok, Reels and Shorts will cover your video before you post.

Trim a video

Cut a video down to the part you want, in seconds.

Mute a video

Remove the sound from a video without re-encoding it.

Convert a video

Turn a MOV, WebM or MKV into an MP4, or an MP4 into a WebM or MOV.

Merge videos

Join clips into one video, in the order you choose.

Audio tools

Image tools

Frame grabber

Save any frame of a video as a full-quality image, or let it pick thumbnails.

Video to GIF

Turn a few seconds of a video into a GIF that loops.

Image resizer

Make a picture smaller or larger, in pixels or by a percentage.

Calculators

Sizes by platform

How these tools work

Each tool does one job on the clip you're about to post. Compress a video to fit Discord, email or WhatsApp. Resize it to 9:16 for TikTok, Reels and Shorts, or to 4:5 for the Instagram feed. Crop it to any box, and turn it the right way up or mirror it. Check what each app's buttons and caption will cover. Trim it to the part that matters, take the sound off it or keep only the sound as an MP3, a WAV or an M4A, turn it into an MP4, a WebM or a MOV, save any frame as a full-resolution PNG or JPG, and turn a few seconds of it into a GIF that loops. Speed it up or slow it down, and join several clips into one. Before you shoot or generate, the aspect ratio calculator gives the pixel size for any shape. Resize a picture, or convert it to JPG, PNG or WebP, iPhone HEIC photos included.

They run on WebCodecs, the video engine already in your browser, through the open-source Mediabunny library. Your file is read and written on your device. These pages can't send it anywhere: their security policy only lets them talk to this site and to the page-view counter. There's no queue, no sign-up and no watermark, and they're free.

They work in current Chrome, Edge, Safari and Firefox, on files up to 2 GB. Anything that re-encodes the picture takes videos up to 15 minutes, and a fast trim, a mute, a turn of an MP4 or a MOV, a conversion that copies the video or an audio extraction has no length limit. Making an MP4 needs a browser that can encode H.264, which Chrome, Edge and Safari can.

The safe-zone table behind the checker is open data under CC BY 4.0. And when the clip you need doesn't exist yet, every tool ends with a button into Kuro, where you make it from a few words.