Convert PNG to JPEG

Turn PNG, the lossless web image format with full transparency support, into JPEG, the ubiquitous compressed photo format from cameras and the web. FileChanger runs the image conversion in one call, no local tooling to install.

In the browser

Upload a file and download the result, no pipeline required. Open the converter.

One API call

POST the file with from=png and to=jpg, get the converted bytes back. Jump to the code.

From an agent

FileChanger ships an MCP server, so agents can run this conversion themselves. See the docs for setup.

Uploading something you care about? How to convert files safely explains what to check before you trust any converter, and Security and data handling describes exactly what we store and for how long.

Convert PNG to JPEG in code

The same call from any language: POST the file to /api/convert, the response body is the converted file.

curl -X POST https://filechanger.io/api/convert \
  -H "X-Api-Key: fc_your_api_key_here" \
  -F "file=@input.png" \
  -F "from=png" \
  -F "to=jpg" \
  -o output.jpg
import requests

with open("input.png", "rb") as f:
    response = requests.post(
        "https://filechanger.io/api/convert",
        headers={"X-Api-Key": "fc_your_api_key_here"},
        files={"file": f},
        data={"from": "png", "to": "jpg"},
    )

response.raise_for_status()
with open("output.jpg", "wb") as out:
    out.write(response.content)
const formData = new FormData();
formData.append("file", fileInput.files[0]);
formData.append("from", "png");
formData.append("to", "jpg");

const response = await fetch("https://filechanger.io/api/convert", {
  method: "POST",
  headers: { "X-Api-Key": "fc_your_api_key_here" },
  body: formData,
});

const output = await response.blob();
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.file.Path;

String boundary = "----FormBoundary" + System.currentTimeMillis();
byte[] fileBytes = java.nio.file.Files.readAllBytes(Path.of("input.png"));

String body = "--" + boundary + "\r\n"
    + "Content-Disposition: form-data; name=\"file\"; filename=\"input.png\"\r\n"
    + "Content-Type: application/octet-stream\r\n\r\n"
    + new String(fileBytes) + "\r\n"
    + "--" + boundary + "\r\nContent-Disposition: form-data; name=\"from\"\r\n\r\npng\r\n"
    + "--" + boundary + "\r\nContent-Disposition: form-data; name=\"to\"\r\n\r\njpg\r\n"
    + "--" + boundary + "--";

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://filechanger.io/api/convert"))
    .header("X-Api-Key", "fc_your_api_key_here")
    .header("Content-Type", "multipart/form-data; boundary=" + boundary)
    .POST(BodyPublishers.ofString(body))
    .build();

HttpResponse<byte[]> response = client.send(
    request, BodyHandlers.ofByteArray());
java.nio.file.Files.write(Path.of("output.jpg"), response.body());
import Network.HTTP.Client
import Network.HTTP.Client.MultipartFormData
import qualified Data.ByteString.Lazy as BL

main :: IO ()
main = do
  manager <- newManager defaultManagerSettings
  initialReq <- parseRequest "POST https://filechanger.io/api/convert"
  let req = initialReq
        { requestHeaders = [("X-Api-Key", "fc_your_api_key_here")] }
  request <- formDataBody
    [ partFileSource "file" "input.png"
    , partBS "from" "png"
    , partBS "to" "jpg"
    ] req

  response <- httpLbs request manager
  BL.writeFile "output.jpg" (responseBody response)

About PNG

Portable Network Graphics (PNG) is an open, lossless raster image format featuring 24-bit RGB color and full alpha-channel transparency. It is the web standard for logos, diagrams, user interface assets, and screenshots where pixel sharpness and clean transparency edges are essential.

About JPEG

JPEG is the standard compressed image format of digital photography and the web. Every browser, phone, camera, and operating system supports it natively, making it the most universally compatible image format available. It uses lossy compression to keep photographic file sizes small, though it does not support transparency and repeated saves can introduce compression artifacts.

Frequently asked questions

How do I convert PNG to JPEG?

Upload your file in the browser converter and pick JPEG as the target, or POST it to /api/convert with from=png and to=jpg. The response body is the converted file.

Is converting PNG to JPEG free?

Yes. Every account gets 200 MB of conversions free, metered on input size. After that you pay only for what you convert, from $0.10 per GB, with no monthly fee. See pricing for the paid tiers.

Is there an API for PNG to JPEG conversion?

Yes, this whole conversion is one POST to /api/convert (the code examples above show it in five languages), plus an MCP server so AI agents can run it directly.

What happens to transparent backgrounds when converting PNG to JPEG?

JPEG does not support alpha transparency. During conversion, transparent areas are replaced with a clean white background.

Why convert PNG to JPEG?

PNG files can be very large for photographic images because PNG uses lossless compression. Converting to JPEG applies lossy compression to significantly reduce file size when alpha transparency is not needed.

Does converting PNG to JPEG lose quality?

Converting PNG to JPEG involves lossy compression, which discards some image data to achieve a smaller file size. FileChanger encodes at high quality so the visual difference is minimal for normal viewing.