Image Resize & Convert API

Resize, crop, rotate, flip and convert images between PNG and JPEG with high-quality resampling and adjustable JPEG quality to shrink file size.

POSThttps://apibox.io.vn/v1/image-resize

Images & Codes▶ Try it online

The image resize API transforms an uploaded PNG or JPEG. Set width and / or height (the other side keeps the aspect ratio) and a fit: inside (default, fits in the box), cover (fills the box and crops the centre, ideal for thumbnails), contain (fits and pads with a background colour) or fill (stretches). crop=x,y,width,height cuts a region first, rotate (90, 180, 270) and flip (horizontal, vertical) fix orientation, and no_enlarge=true never upscales.

Shrinking uses area averaging, which keeps fine details sharp without aliasing; enlarging uses bilinear interpolation. Output format=jpeg with quality (1–100, default 82) to reduce size; transparent areas are flattened on the background colour. Headers report the new size and the input / output byte counts.

Images up to 25 megapixels and the file size of your plan are accepted; everything runs in memory and nothing is stored.

Parameters

Name	In	Type	Required	Default
`file`	body	file	yes		PNG or JPEG (multipart, raw body or `file_base64`).
`width`	query\|body	number	no		Target width (px).
`height`	query\|body	number	no		Target height (px).
`fit`	query\|body	string	no	`inside`	`inside`, `cover`, `contain`, `fill`.
`crop`	query\|body	string	no		`x,y,width,height` before resizing.
`rotate`	query\|body	number	no		90, 180 or 270.
`flip`	query\|body	string	no		`horizontal` or `vertical`.
`format`	query\|body	string	no		`png` or `jpeg` (default: same as input).
`quality`	query\|body	number	no	`82`	JPEG quality 1–100.
`background`	query\|body	string	no	`ffffff`	Padding / flatten colour.

Example

curl -X POST "https://apibox.io.vn/v1/image-resize?width=400&height=400&fit=cover&format=jpeg" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "0=@./my-file" \
  -o output

const form = new FormData();
form.append('0', fileInput.files[0]);

const res = await fetch('https://apibox.io.vn/v1/image-resize?width=400&height=400&fit=cover&format=jpeg', {
  method: 'POST',
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
  body: form,
});
console.log(await res.json());

import requests

res = requests.post(
    "https://apibox.io.vn/v1/image-resize?width=400&height=400&fit=cover&format=jpeg",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    files={"0": open("my-file", "rb")},
    timeout=30,
)
open("output", "wb").write(res.content)

<?php
$ch = curl_init('https://apibox.io.vn/v1/image-resize?width=400&height=400&fit=cover&format=jpeg');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => ['0' => new CURLFile('my-file')],
]);
$response = curl_exec($ch);
file_put_contents('output', $response);

Response

binary image/jpeg

Use cases

Thumbnails and avatars from user uploads
Shrink photos before storing them
Convert PNG screenshots to lighter JPEG
Square images for marketplaces and social networks

FAQ

Is EXIF orientation applied?

Not automatically; use rotate= when a photo appears sideways (image-metadata tells you the EXIF orientation).

Is WebP supported?

Not yet: PNG and JPEG in and out.

What is the size limit?

25 megapixels and the file size of your plan (5–50 MB).

Image Resize & Convert API

Parameters

Example

Response

Use cases

FAQ

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