maxresdefault
Usually 1280 x 720 when available.
Measure thumbnail availability
YouTube Thumbnail Size Checker
Check maxresdefault, SD, HQ, MQ, and default thumbnail candidates with actual browser-detected dimensions.
Try:
Direct answer
The YouTube Thumbnail Size Checker loads common thumbnail candidates in your browser and reports actual dimensions, availability, aspect ratio, and fallback guidance for each candidate.
Detailed guide
Check the real image size, not just the filename
A thumbnail URL can look like a high-resolution file even when the image that loads is smaller, missing, or placeholder-like. That is why TubeSnaps checks the actual natural width and height in the browser instead of relying only on the filename.
This page is most useful when maxresdefault is not working, when an image looks blurry, or when you need to decide whether sddefault, hqdefault, mqdefault, or default is a safer fallback.
The size checker does not call the YouTube API or guarantee a specific asset exists. It shows what your browser can load from common public candidates and gives a practical explanation of the result.
How it works
Measure thumbnail candidates before you reuse them
The size checker is a diagnostic workflow: compare expected filenames with the dimensions your browser can actually load.
- 1
Enter a video URL or ID
TubeSnaps extracts the video ID from common YouTube URL formats or accepts a bare 11-character ID.
- 2
Load thumbnail candidates
The browser checks common public image URLs such as maxresdefault, sddefault, hqdefault, mqdefault, and default.
- 3
Compare actual dimensions
TubeSnaps reads natural width and height where possible instead of relying only on expected dimensions.
- 4
Choose a fallback
If maxresdefault is missing or suspicious, use the recommended lower-size candidate.
Visual explainer
Thumbnail size ladder
Move from the largest useful candidate down to reliable smaller fallbacks when a video does not expose every size.
sddefault
Often 640 x 480 and useful as a larger fallback.
hqdefault
Common 480 x 360 fallback.
mq/default
Smaller references for quick previews.
Sizes and formats
Thumbnail size reference and fallback meaning
Use actual dimensions to separate strong candidates from small fallbacks or missing assets.
| Item | Size or value | Format | Best use | Note |
|---|---|---|---|---|
| maxresdefault | Expected around 1280 x 720 | JPG | Best large 16:9 candidate | May be unavailable or suspiciously small. |
| sddefault | Often 640 x 480 | JPG | Large fallback | Good when maxres does not load. |
| hqdefault | Often 480 x 360 | JPG | Reliable fallback | Usually enough for small previews. |
| mqdefault | Often 320 x 180 | JPG | Lightweight preview | Useful for quick references. |
| default | Often 120 x 90 | JPG | Tiny fallback | Avoid for polished design work. |
Image examples
What the image candidates can mean
Expected HD
A loaded 1280 x 720 candidate usually works for creator image previews and blog use.
Small fallback
A 120 x 90 result means the image is only useful as a tiny reference, not a production asset.
Suspicious result
A large filename returning a small image should be treated as a fallback signal.
Design and usage tips
Use thumbnails with clearer judgment
Use dimensions as a quality gate
Do not choose a thumbnail just because the filename says maxres; confirm the loaded size.
Match the image to the use case
Large previews need stronger candidates, while small notes can use lighter fallback images.
Prefer reliable over broken
A smaller available image is better than embedding a missing or placeholder-like high-resolution URL.
Popular use cases
When this workflow helps
Diagnose blurry thumbnails
Check whether the loaded image is smaller than expected before using it in a design or article.
Fix maxres issues
Confirm whether maxresdefault is truly available, missing, or placeholder-like.
Pick an embed image
Choose a practical fallback for pages, previews, or documentation.
What the results mean
Read the output with confidence
Actual size
The width and height reported by the browser after loading the image.
Expected size
The common target dimension for that filename, used only as a reference.
Placeholder suspected
A large filename may return a small image, which usually means a better fallback is needed.
Aspect ratio
A quick way to spot whether a candidate matches a 16:9 thumbnail workflow or a smaller generated preview.
Common mistakes
Avoid misleading thumbnail workflows
Trusting the filename only
A URL containing maxresdefault does not prove the loaded image is actually 1280 x 720.
Using a failed image in production
If a candidate is unavailable, choose a fallback instead of embedding the missing URL.
Ignoring generated preview limits
0.jpg, 1.jpg, 2.jpg, and 3.jpg can be useful but may not represent the custom thumbnail.
Trust and compliance
Local-first, permission-aware guidance
No YouTube API dependency
The current checker reads public image candidates and browser-detected dimensions.
No stored URLs
The tool is designed to avoid storing full YouTube URLs or user search history.
Transparent fallback logic
The result text explains why a fallback may be safer than the largest-looking filename.
Official context
Sources and platform context
Related workflows
Next steps after this page
Why maxresdefault is not working
YouTube Thumbnail Sizes
Thumbnail Fallbacks
Related tools
Keep working with this video
FAQ
Common questions
Why does maxresdefault sometimes return a small image?
A missing high-resolution asset can resolve to a fallback-like placeholder. TubeSnaps marks suspicious small dimensions so you can choose a better fallback.
What fallback order should I try?
Try maxresdefault, sddefault, hqdefault, mqdefault, then default.
Does this use the YouTube API?
No. The first version checks public image candidates in the browser and reads natural image dimensions.