AltF Creator

YouTube thumbnail size and requirements

YouTube recommends a 16:9 thumbnail for videos (9:16 for Shorts) with a minimum width of 640 pixels. 1280 x 720 is the long-standing standard and YouTube now recommends up to 3840 x 2160. Use JPG or PNG, keep it under 2 MB if you upload from a phone (50 MB from a computer), and note that your channel must be verified to upload a custom thumbnail.

  • Free, no sign-up
  • Runs in your browser
  • Limits sourced from each platform
  • No fake scores or view predictions

Runs in your browser — nothing is uploaded.

Thumbnail checklist

  • 16:9 canvas, at least 1280 x 720.
  • JPG or PNG under 2 MB so it uploads from a phone too.
  • Three or four words at most, large enough to read on a phone.
  • Faces and the subject away from the bottom-right corner, where the duration badge sits.
  • High contrast between text and background, in both light and dark mode.

Test it small

Most views come from phones, where a thumbnail is about the size of a stamp. Shrink your design to 320 pixels wide before you upload: if you cannot read it, neither can a viewer.

YouTube thumbnail size and requirements: questions and answers

Why can't I upload a custom thumbnail?

YouTube only allows custom thumbnails on verified channels. Verify your channel with a phone number in YouTube Studio.

What size is a YouTube Shorts thumbnail?

9:16, with a minimum height of 640 pixels. Custom Shorts thumbnails are uploaded from YouTube Studio on a computer.

Creator tools and guides

Full creator studioAll seven tools, the workflow, platform limits and the tool directory.YouTube title length checkerCheck a YouTube title's length, keyword position and readability, preview it as a search result, and compare two titles. Free, in your browser.YouTube chapters generator and timestamp checkerPaste your timestamps, fix every error YouTube would reject (00:00 start, 3+ chapters, 10 seconds each) and copy a clean chapter list for your description.Hashtag cleaner and counterPaste messy tags and get clean, unique hashtags checked against each platform's rules: YouTube's 60-hashtag cap, Instagram's 30, TikTok and X caption counts.Social media character limits, with a live checkerCharacter limits for YouTube, Instagram, TikTok, X, Threads, LinkedIn, Pinterest and Facebook, with a live checker that shows what appears before "more".Video aspect ratio and crop calculatorWork out video and image sizes for any aspect ratio, see how a 16:9 frame crops to 9:16 or 4:5, and use presets for YouTube, Shorts, Reels, TikTok and more.YouTube earnings calculator (with your own RPM)Estimate YouTube ad revenue from your own RPM and views, price a sponsorship from a CPM, and work out engagement rate. No made-up averages.Upload schedule planner and content calendarPick your posting days, add a working title to each slot and export the plan to Google Calendar, Apple Calendar or Outlook as an .ics file.YouTube Shorts guide: length, size and what to checkYouTube Shorts length (up to 3 minutes), vertical 9:16 size, thumbnails, hashtags and a checklist for your first Shorts, with free tools.Instagram Reels guide: size, captions and hashtagsInstagram Reels size (1080 x 1920), caption limit (2,200 characters, ~125 shown), hashtag limit (30) and a checklist, with free checking tools.TikTok caption length and hashtag guideTikTok caption limit (4,000 characters), bio limit (80), username limit (24), how hashtags count and how to write captions that get read.The video creator workflow, step by stepA practical step-by-step video creator workflow from idea to analytics, with a free AltFTool tool for each stage.

69 free creator tools on AltFTool

Focused tools for one job each, grouped by the part of the work they help with. Each tool says whether it runs in your browser or uses a server.

Video editing and files

Captions, subtitles and transcripts

Titles, thumbnails and descriptions

See all 69 creator tools

Get your channel found

Links from real, relevant sites help a channel, podcast or portfolio show up in search. These AltFTool lists are checked by hand; pick the ones that fit your niche and skip any that ask you to pay for links.

Free backlink sitesA checked list of sites where you can list a channel, podcast or portfolio.Community and social sitesProfiles and communities where a creator link is allowed.Content platformsPlatforms where you can republish or embed your work.Free directory submissionsDirectories that accept a free listing.Image promptsPrompt ideas for thumbnails and channel art.Free AI toolsFree AI tools for scripts, voice and editing.

Everything you type into AltF Creator stays in your browser. Your upload plan is saved on this device only, and nothing is sent to AltFTool or any platform.