Creator workbench catalog

Browse exact tasks, licensed drawings and font families by category.

About these free tools - how they work and who makes them

Why Koldflux tools process files in your browser, how platform references are reviewed, and what we do and do not collect.

Aspect ratio converter - video and image, free

Crop video or images to 9:16, 16:9, 1:1, 4:5, 4:3 or 21:9 in your browser. Free, no upload, no watermark.

Aspect ratio calculator - simplify a ratio or solve a missing side

Reduce any width × height to its simplest ratio, and solve for the missing side when you know the ratio and one dimension.

Audio bitrate calculator - size of an audio track

Estimate how much space an audio track takes at a given bitrate, and what that costs inside a video file.

AVI won't upload to LinkedIn? What to check

Yes - LinkedIn lists AVI for organic video on desktop, iOS and Android. Check the upload surface first, then the actual codec, duration and file size. This compatibility record does not diagnose your particular file.

AVI won't upload to TikTok? What to check

AVI is not listed for TikTok Content Posting API uploads. Check the upload surface first, then the actual codec, duration and file size. This compatibility record does not diagnose your particular file.

AVI won't upload to YouTube Shorts? What to check

Yes - AVI is listed among YouTube supported upload formats. Check the upload surface first, then the actual codec, duration and file size. This compatibility record does not diagnose your particular file.

A practical video format for TikTok: MP4 and H.264

For TikTok’s Content Posting API, MP4 with H.264 is the documented recommendation. AAC is this tool’s audio export choice, not an API requirement established by that source. Native composers may differ; no format guarantees acceptance.

Accidentally muted a video - can you get the audio back?

If you only muted a player, unmute it. If you exported with this site’s mute tool, the output has no audio stream; recover sound from the original or an earlier project version. Other editors may retain a disabled track.

Add a watermark to a video - free, no upload

Burn your own logo onto a video, with control over position, size and opacity. Free, runs in your browser, and adds no watermark of its own.