Watermark Photos Online

Add a text and / or logo watermark to JPEG or PNG photos: 9 positions or tiled diagonal text, opacity, size, margin; up to 20 images per call as a ZIP.

Result

Press “Run” to see the result.

Upload an image as multipart file (or several files for a batch) with a watermark text, a logo (PNG with transparency or JPEG) or both. position is one of top-left, top, top-right, left, center, right, bottom-left, bottom, bottom-right or tile (the watermark repeated over the whole photo in staggered rows, rotated by rotation, default 30°). scale sets the watermark width as a share of the image width (default 0.3), opacity 0–1 or 0–100, margin a share of the shorter side, spacing the gap between tiles. Text uses Be Vietnam Pro (full Vietnamese) in color with a thin contrasting outline (stroke, outline=false to remove); with a logo and text the text is placed under the logo (layout=stack) or separately (text_position).

One image returns the image (same format, or format=png|jpeg, quality); several images return watermarked.zip. max_width resizes before watermarking. Limits: 25 megapixels per image, 100 MP and 20 images per request, and your plan's upload size. Images are processed in memory and not stored.

Use this in your code

curl -X POST "https://apibox.io.vn/v1/image-watermark" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "file=@./my-file" \
  -o output

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

const res = await fetch('https://apibox.io.vn/v1/image-watermark', {
  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-watermark",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    files={"file": open("my-file", "rb")},
    timeout=30,
)
open("output", "wb").write(res.content)

<?php
$ch = curl_init('https://apibox.io.vn/v1/image-watermark');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => ['file' => new CURLFile('my-file')],
]);
$response = curl_exec($ch);
file_put_contents('output', $response);

API documentation → Get a free API key

FAQ

Which formats are supported?

JPEG and PNG in and out. The logo can be a transparent PNG.

How do I watermark many images?

Send several files in the multipart request (up to 20); the response is a ZIP with one watermarked image per file.

Does Vietnamese text work?

Yes: the text is drawn from the Be Vietnam Pro font outlines, with all diacritics.