Serve a transparent GIF from NodeJS

transparent-gif.js

// Two ways to serve transparent GIF

var buf = new Buffer([
    0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00, 0x01, 0x00, 
    0x80, 0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x2c, 
    0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 
    0x02, 0x44, 0x01, 0x00, 0x3b]);

res.send(buf, { 'Content-Type': 'image/gif' }, 200);

// --- OR ----

var buf = new Buffer(35);
buf.write("R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=", "base64");
res.send(buf, { 'Content-Type': 'image/gif' }, 200);

@elhardoum Not sure where you got these from. I don't see those stylings in the most recent version of Chrome 98.0.4758.80.

When I inspect the img element they don't show up (even when ticking the Show all checkbox).

But the 35 byte one shows up as a white pixel and the 43 byte one is transparent and invisible on a black background.

@chrisspiegl my bad, didn't pay close attention - the image is shown on a website not the standard chrome image viewer page. I'll improve my answer, ty

@chrisspiegl solution worked like a charm. Displays perfectly transparent. Thanks