Online Tool Store
· 3 min read
How to Generate a BlurHash Placeholder
Heshan Fernando
Co-founder & COO
Lazy-loaded images can leave a blank rectangle while the real image downloads. A BlurHash gives you a tiny text placeholder that expands into a soft preview of the image, making the loading state feel more intentional.
A BlurHash generator encodes an image into a short string, lets you tune component counts, decodes existing hashes for checking, and shows round-trip color error.
What BlurHash involves
BlurHash represents an image as a compact string, often around 20 to 30 characters. The app or site decodes that string into a blurred placeholder while the real image loads.
The placeholder is not meant to be detailed. It captures broad color and shape so the layout feels alive before the final image arrives.
Why people get stuck here
Component counts affect quality and length. More components can preserve more structure, but the hash becomes larger and may not be worth the added complexity.
Another issue is trusting a hash without decoding it. A quick decode preview shows whether the placeholder actually resembles the image enough for your use case.
| Choice | Effect | Watch Out |
|---|---|---|
| Fewer components | Shorter hash | Less structure |
| More components | Better shape | Longer string |
| Decode preview | Quality check | Still intentionally blurred |
| Color error | Round-trip clue | Use as guidance |
What a good BlurHash looks like
The dominant colors feel right
The placeholder should roughly match the image’s mood and color balance.
The string stays compact
Do not chase detail that a blurred placeholder does not need.
The decoded preview is checked
Previewing the hash catches bad inputs, strange crops, or overly sparse settings.
Common mistakes to avoid
- Expecting BlurHash to look like a thumbnail.
- Using too many components for a tiny visual gain.
- Forgetting to decode and inspect the hash.
- Treating color error as the only quality measure.
- Using placeholders that clash strongly with the final image.
How to do it with BlurHash Generator
Online Tool Store’s BlurHash Generator encodes images into BlurHash strings, tunes component counts, decodes hashes, and shows color error.
- Open the BlurHash Generator.
- Choose the image you want to encode.
- Adjust component counts if needed.
- Copy the generated BlurHash string.
- Decode it to preview the placeholder.
- Use the string in your app’s lazy-loading image workflow.
It is useful for developers building image-heavy pages, feeds, galleries, and media cards.
Frequently asked questions
Is BlurHash an image format?
No. It is a compact string that can be decoded into a blurred placeholder.
Should the placeholder be sharp?
No. BlurHash is meant to be soft and approximate while the real image loads.
Why tune component counts?
Component counts control how much color and structure the hash stores. More is not always better.
Final thought
Generate a BlurHash when blank image loading feels too abrupt. Keep it compact, preview the decode, and let the real image do the detailed work.