Convert JPEG to PNG

Turn JPEG, the ubiquitous compressed photo format from cameras and the web, into PNG, the lossless web image format with full transparency support. 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=jpg and to=png, 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 JPEG to PNG 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.jpg" \
  -F "from=jpg" \
  -F "to=png" \
  -o output.png
import requests

with open("input.jpg", "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": "jpg", "to": "png"},
    )

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

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.jpg"));

String body = "--" + boundary + "\r\n"
    + "Content-Disposition: form-data; name=\"file\"; filename=\"input.jpg\"\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\njpg\r\n"
    + "--" + boundary + "\r\nContent-Disposition: form-data; name=\"to\"\r\n\r\npng\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.png"), 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.jpg"
    , partBS "from" "jpg"
    , partBS "to" "png"
    ] req

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

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.

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.

Frequently asked questions

How do I convert JPEG to PNG?

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

Is converting JPEG to PNG 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 JPEG to PNG 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.

Why convert JPEG to PNG?

PNG uses lossless compression and supports an alpha channel for transparency. Converting a JPEG to PNG stops further generation loss during image editing, graphic design, and asset export, making it ideal when you need to edit the image or add transparency in an editor.

Does converting JPEG to PNG improve the image quality?

No. PNG compression is lossless, so it preserves the exact pixels of the decoded JPEG without adding new compression artifacts, but it cannot restore detail or sharpness lost when the original JPEG was compressed.

Will converting JPEG to PNG create a transparent background?

No. JPEGs have no alpha channel, so the resulting PNG starts with an opaque background matching the source image. Converting to PNG gives the file transparency support so you can edit and remove backgrounds in image tools afterwards.