YouTube Thumbnail Tester
See your thumbnail where viewers will: on a phone, in Up next and on the home feed, next to the videos that rank for your search today. Then checks that give the same answer every time. Free, no sign-in.
Checks
Studio puts your own channel's history next to every test ("your 4 bread videos did 2.1x your usual"), follows channels like yours, and shows how every video really did. Free to start.
Try it in StudioOne video here. Your whole channel in ChannelGrade.
Connect your channel and every upload is pulled in on its own, no pasting links.
Free to connect. A plan adds the written read of each upload: why viewers left, what comments ask for, what to make next.
Every video against the middle of your own others of the same kind, at the same age. Shorts with Shorts.
On screen: one still shot of the pan while the voice-over explains the rule. Said: "so the reason this works is". Likely why: the payoff already happened, and the explanation is slower than everything before it.
Why: StarterYour title and thumbnail in real YouTube search, next to the videos you are up against. Checks that give the same answer every time, no made-up scores.
Channels like yours, each video against that channel's own usual. You see the moment one of theirs takes off.
Mostly excited and asking for more. A few viewers say the music drowns out your voice in the middle.
They ask you to make
do this in the snow next PLEASE
what spices did you use at 2:10?
They ask
where is that pan from??
how many hours was the hike in
Questions about testing thumbnails
How do I test my YouTube thumbnail?
Upload it above, type your title and the search you want to show up in, and press Test it. You see your thumbnail and title on a phone, in the Up next list and on the home feed, next to the videos that rank for that search today, plus checks on text size, brightness, color and look-alikes.
Is this thumbnail tester free?
Yes, 5 tests a day with no sign-in. ChannelGrade Studio adds 3 more a month for free, with your own channel's history next to every test, and plans test without a limit.
What size should a YouTube thumbnail be?
YouTube asks for 1280x720 pixels (16:9), under 2 MB, as a JPG, PNG or GIF. The tester checks all three.
How big should the text on a thumbnail be?
The smallest place YouTube shows a thumbnail is the Up next list, about 168x94 pixels on a computer. Text at least 8% of the thumbnail's height (about 7 pixels tall there) still reads. The tester measures every word it can read and tells you the smallest.
Do you give my thumbnail a score?
No, on purpose. Nobody can score a thumbnail and know how it will do: the same thumbnail gets 500 views on one channel and 5 million on another. The tester shows it where viewers will see it and checks what can be measured, so the same file always gets the same answer.
Why do the results change from day to day?
The comparison uses the videos ranking for your search today, so it moves when YouTube's results move. The measurements of your own thumbnail never change.
Get the full read of every video you upload
Thumbnail Tester stays free here. A plan reads every video on your channel for you: what to change, where viewers left and why, what your comments ask for, and what to make next. It also follows channels like yours and checks every title and thumbnail before you post.
- 1 channel, every video compared with your usual
- Views per day and the retention curve (with YouTube Studio)
- Where viewers came from and who watched
- 5 free runs a day of every tool
- 1 channel, every new upload read for you
- Where viewers stop watching and why (with YouTube Studio)
- What to change on each video, from its own numbers
- What your comments ask for, counted and quoted
- What works on your channel, and what to make next
- Follow 10 channels like yours and see what takes off for them
- Check every title and thumbnail before you post
- A weekly email: what moved and what to make next
- 30 tool credits/month
- 3 channels, every new upload read for you
- Where viewers stop watching and why (with YouTube Studio)
- What to change on each video, from its own numbers
- What your comments ask for, counted and quoted
- What works on your channel, and what to make next
- Follow 30 channels like yours and see what takes off for them
- Check every title and thumbnail before you post
- A weekly email: what moved and what to make next
- 100 tool credits/month
- Priority support
- 20 channels, every new upload read for you
- Where viewers stop watching and why (with YouTube Studio)
- What to change on each video, from its own numbers
- What your comments ask for, counted and quoted
- What works on your channel, and what to make next
- Follow 100 channels like yours and see what takes off for them
- Check every title and thumbnail before you post
- A weekly email: what moved and what to make next
- 500 tool credits/month
- Priority support
Monthly, cancel anytime. Payment by Stripe. Plans include more runs of every tool.
Want to try Starter first? Get it free for 30 days by following ChannelGrade on X.