Free tools for clippers and podcasters

Small tools that run in your browser. Nothing is uploaded and there is nothing to sign up for.

• Aspect ratio calculator for videoType a width and height and the calculator gives the simplified ratio, so 1920 x 1080 is 16:9. It also resizes while keeping that ratio, finds the largest 9:16 window inside a wider frame (607 x 1080 from 1920 x 1080), and checks the shape against what each platform publishes. It runs in your browser and uploads nothing.
• Caption character counter for TikTok, Reels and ShortsPaste your text and the counter shows characters, words, lines, hashtags and mentions, then checks them against the limits each platform publishes: Instagram 2,200 characters, YouTube Shorts titles 100. We could not confirm a number for ordinary TikTok captions on TikTok's own pages, so the tool shows none and lets you set your own. It runs in your browser.
• Hook generator for YouTube ShortsType what your clip is about and get five opening lines, a text call to action and hashtag ideas. Paste a transcript and the tool also pulls the strongest line already in it. It runs in your browser, uploads nothing and uses sentence templates, not AI, so you edit the lines and keep only what the clip delivers.
• Reels safe zone checkerThis free checker draws the edges of a vertical frame that apps may cover with buttons and captions, tests whether your caption block sits inside them, and exports a transparent PNG overlay. Meta publishes margins for Reels ads only. For everything else it draws KeyMo's own conservative margins and labels them that way. Your files never leave the browser.
• SRT to VTT converterPaste SRT text or add .srt files and the tool writes a WebVTT file: a WEBVTT header, a full stop instead of a comma before the milliseconds, and cue text escaped so the file is valid. It also converts VTT back to SRT. Cues it has to change or leave out are listed by line, and nothing leaves your browser.
• Transcript cleanerPaste a WebVTT, SRT or SBV caption file, or any transcript with timestamps, and this tool returns readable paragraphs. It removes cue timings and numbers, merges caption lines that repeat, drops sound cues such as [Music] and filler such as um and uh. Everything runs in your browser and nothing is uploaded.
• Video file size calculatorFile size is bitrate times length, divided by eight. Add the video and audio bitrates in kilobits per second, multiply by the seconds, and divide by 8 to get bytes. One minute at 8 Mbps video and 128 kbps audio comes to about 61 MB. The calculator does the sum for you and checks the result against upload limits read from each platform's own pages.
• Video length checkerChoose a video file or type a length such as 2:45, and the checker shows whether it fits each platform's published limit: 3 minutes for a YouTube Short, 20 minutes for an Instagram Reel, 60 minutes on TikTok and more. It reads only the length and frame size in your browser, so nothing is uploaded.
• YouTube chapter generator and timestamp checkerPaste your timestamps and titles, one per line. The tool cleans the format, sorts them, and checks the three rules on YouTube's Video Chapters page: the first timestamp is 00:00, there are at least three, and each chapter lasts at least 10 seconds. It does not write the titles for you, and nothing leaves your browser.