M
API Matrix

ReSmush.it API

⭐ Beginner's Pick Photography / No Auth Required Beginner HTTP
Free to Use Varies (check documentation)
72 Score
Grade B
Visit Official Site Compare Alternatives

Overview

ReSmush.it is a free image optimization API that compresses photos to reduce file size without visibly losing quality. You simply pass an image URL and receive a smaller, web-ready version in return. No API key is required, making it one of the easiest image APIs to get started with.

💡

Beginner Tip

Use the qlty parameter (0-100) to control compression strength; a value of 82 is a good default that balances quality and file size.

Available Data

image URLs in multiple sizes
photographer credit
image dimensions
download link
color data
Use case: Integrate photo optimization data into web and mobile applications

Example Response

JSON Response 
{
  "id": "Dwu85P9SOIk",
  "urls": {
    "full": "https://images.unsplash.com/photo-...",
    "regular": "https://images.unsplash.com/photo-...?w=1080",
    "thumb": "https://images.unsplash.com/photo-...?w=200"
  },
  "width": 4000,
  "height": 3000,
  "user": {
    "name": "John Doe",
    "username": "johndoe"
  }
}

Field Reference

src URL of the original uncompressed image you submitted.
dest URL of the optimized image ready for download.
src_size File size of the original image in bytes.
dest_size File size of the optimized image in bytes.
percent Percentage of size reduction achieved by the optimization.

Implementation Example 

// ⚠️ Note: This URL may be a documentation page. Check official docs for actual API endpoint.
const url = "https://resmush.it/api";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

Error: Unable to open source file The image URL provided is not publicly accessible or the server returned an error.
✓ Make sure the image URL is publicly reachable and returns a valid image content type.
Response shows no size reduction The image was already highly compressed or the quality setting was set too high (close to 100).
✓ Lower the qlty value (try 75-85) for more aggressive compression.
Empty or invalid JSON response The API may be temporarily unavailable or the request timed out on a large image.
✓ Retry the request and consider using smaller images (under 5 MB) for reliable results.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 15/20
🔒 Security 5/15
🛠 Developer XP 15/20
✓ Reliability 7/15
Response Time 317ms

Fully tested on Apr 5, 2026

Technical Specifications

Auth No Auth
HTTPS NO
CORS UNKNOWN
Category Photography
Difficulty Beginner
Verified: 2026-04-04

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