image/jpeg
JPG test files generated in your browser
Generate JPG fixtures locally for upload limits, dimensions, lossy compression, thumbnails, MIME checks, and browser automation.
Verified . Generated Blob signature and decoded dimensions are checked locally; no stable JPG URL is published.
Identify JPG files
- Magic signature
FF D8 FF- Registered MIME
image/jpeg
JPEG is a marker-based image stream. The extension does not describe color profile, orientation, or progressive encoding.
Choosing JPG
JPG is broadly supported by browsers and image libraries. It suits photographic content but does not preserve transparency.
Generate JPG when broad compatibility matters more than exact pixel preservation.
Decode every generated output and verify dimensions and MIME after optimization.
Common test cases
- Upload and MIME validation
- Lossy compression comparisons
- Responsive image and thumbnail tests
Invalid and boundary cases
- Renamed non-JPEG content
- Truncated end-of-image marker
- Large dimensions with a small compressed size
JPG fixture matrix
| File | Dimensions | Traits | MIME | Size |
|---|---|---|---|---|
| Square 1024x1024 JPGsquare-1024x1024.jpg | 1024 × 1024 | square | image/jpeg | 55 KB |
Verify the representative fixture
Each command downloads square-1024x1024.jpg and uses its published URL. The Node.js and Python examples also verify the exact byte count and SHA-256 digest.
Download the published fixture and inspect its response headers before saving the exact bytes.
curl --fail --location --silent --show-error \
--output square-1024x1024.jpg \
--write-out 'status=%{http_code}\ncontent_type=%{content_type}\nbytes=%{size_download}\n' \
'https://assets.testfiles.dev/image/square-1024x1024.jpg'Save the stable fixture URL without changing the published byte stream.
wget --output-document='square-1024x1024.jpg' 'https://assets.testfiles.dev/image/square-1024x1024.jpg'Verify the downloaded byte count and SHA-256 digest in a Node.js workflow.
import assert from "node:assert/strict";
import { createHash } from "node:crypto";
const response = await fetch("https://assets.testfiles.dev/image/square-1024x1024.jpg");
assert.equal(response.ok, true);
assert.match(response.headers.get("content-type") ?? "", /image\/jpeg/i);
const bytes = Buffer.from(await response.arrayBuffer());
assert.equal(bytes.length, 56111);
assert.equal(createHash("sha256").update(bytes).digest("hex"), "0d928f9817e86c6c78edd57019a699f1a3aa71ef21fb4e6ac7fcf858ff7bec76");
console.log("Verified square-1024x1024.jpg", bytes.length, "bytes");Verify the same fixture from a Python test or processing pipeline.
import hashlib
import requests
url = "https://assets.testfiles.dev/image/square-1024x1024.jpg"
response = requests.get(url, timeout=30)
response.raise_for_status()
assert "image/jpeg" in response.headers.get("content-type", "")
assert len(response.content) == 56111
assert hashlib.sha256(response.content).hexdigest() == "0d928f9817e86c6c78edd57019a699f1a3aa71ef21fb4e6ac7fcf858ff7bec76"
print("Verified square-1024x1024.jpg", len(response.content), "bytes")