YouTube creator tools

Paste a video link (any form: watch?v=, youtu.be, Shorts, embeds, live) to see every size of thumbnail YouTube serves, from the 1280×720 maxresdefault down to 120×90, each with a download button. The maximum-resolution image exists only when the video was uploaded at 720p or more; the tool says when it’s missing.

Check your thumbnail opens your own image (it never leaves your computer) and checks it against YouTube’s requirements: 16:9 (9:16 for a Short), at least 640 pixels wide, a recommended 3840×2160, and at most 2 MB when uploaded from the mobile app or 50 MB from a computer. It then draws it at the sizes it appears on YouTube — home feed, search results, the Up next sidebar, a phone feed, and small rows — on a dark or light background, with the duration badge in the corner and an optional red watched bar, so you can see whether the text still reads. Shorts crop shows which part of a landscape image survives in a 9:16 frame.

Paste a chapter list, or a whole description. Timestamps are found anywhere on a line (0:00 Intro, Intro - 0:00, [01:30] Setup). The tool checks YouTube’s rules: the first chapter starts at 0:00, there are at least three, they’re in ascending order, and each is at least 10 seconds long (give the video’s length to check the last one too). It writes the list back out in 0:00 or 00:00 style, adds hours when needed, and Shift moves every chapter after the first by a fixed time — for when you trim the intro.

Paste any link to get the video and playlist IDs and the start time, then a short share link with a start time (youtu.be/ID?t=90), the watch link, the link inside its playlist, a timestamp to paste into a comment, and the embed URL. The embed code uses YouTube’s privacy-enhanced mode (youtube-nocookie.com) unless you untick it, and supports the documented player parameters: start and end, autoplay (always muted, since browsers block autoplay with sound), loop (which needs the playlist parameter set to the same video), controls, captions on and their language, related videos from the same channel only, and inline playback on iPhone. Responsive wraps the player in a box that keeps 16:9 (or 9:16 for a Short) at any width.

Counts against the limits YouTube’s API enforces: a title of 100 characters, a description of 5000 bytes (an emoji or accented letter takes two to four), no < or > in either, and 500 characters of tags — where the commas count and a tag with a space is counted with quotes around it. It lists the hashtags (up to three can appear above the title; with more than 60, YouTube ignores them all), the links, and any chapters in the description, and shows roughly how the title and description look on the watch page, in search, and on a phone. Those previews are approximate: YouTube cuts text by width and changes its layout often.

Paste or open SRT, WebVTT, or SBV (YouTube’s own format) captions; the format is detected. Convert between them, shift every cue earlier or later, fix a frame-rate mismatch (23.976 ↔ 25, 24 ↔ 25, 29.97 → 30), merge short neighbouring cues, or split long ones. The tool flags cues faster than 20 characters a second, a common limit for comfortable reading.

Readable transcript turns captions into paragraphs: it removes the repeated words of rolling auto-generated captions and tags such as [Music], starts a new paragraph at each pause, and can drop filler words. It’s a quick way to get a blog post or show notes from a video.

Paste a script to count words and see how long it takes to read at your speaking speed (and at 130, 150, and 170 words a minute). Start teleprompter scrolls it full screen with a reading line: space or a click starts and stops it, the arrow keys change the speed, and Mirror flips the text for a beam-splitter prompter. Speed, size, and mirroring are remembered.

YouTube’s recommended encoding: video bitrates for SDR and HDR at standard (24–30 fps) and high (48–60 fps) frame rates, from 360p to 8K; the container, codec, colour, and audio settings; and an upload-size estimate for a given length.

The limits and recommendations come from YouTube’s documentation: Add video thumbnails, Video chapters, Hashtags, Recommended upload encoding settings, the Data API videos resource (title, description, and tag limits), and the IFrame player parameters. Check them before relying on a number: YouTube changes them from time to time.

The teleprompter (Script & teleprompter tab) is the presentation view: Space plays and pauses, ↑ ↓ change the speed, + − the text size, M mirrors for a beam-splitter prompter, Home restarts. It reads the saved script, so it can be opened from any tab. Press ⛶ Present (beside Share link) or F to open it; Esc or F closes it and T switches between dark and light. It goes full screen where the browser allows, otherwise it fills the window, and keeps the screen awake. Controls and the pointer fade after a few idle seconds.

Share link → Link options can make a link that opens straight into this view and starts by itself. With Start automatically, the script starts scrolling as soon as the page opens. Browsers only allow real full screen after a click, so a link opened cold shows the view filling the window with a “Click for full screen” button.

Share link copies a URL that opens this tool on the current tab with your settings. Hand-written links work too: Thumbnails ?v=<link or ID>, Chapters ?ch=<the list>, Links ?u=<link>&t=1:30, Title ?title=…. For example ?u=https://youtu.be/dQw4w9WgXcQ&t=0:43.