I've been messing around for a while with the @solana/web3.js browser bundle (https://docs.solana.com/developing/clients/javascript-api#bundle) and I'm having some difficulty sending a transaction. My current code utilizes the sendAndConfirmTransaction method, but I'm seeing the following error:

ReferenceError: Buffer is not defined
    at toBufferLE (browser.js:48:24)
    at bigIntLayout.encode (bigint.ts:30:19)
    at Structure.encode (Layout.js:1092:36)
    at encodeData (instruction.ts:32:15)
    at SystemProgram.transfer (system.ts:796:14)
    at sendTransaction ((index):88:36)
    at async Proxy.submitData ((index):65:9)

Below is the function I'm currently working with.

async function sendTransaction() {
  console.log('Sending transaction...')
  try {
    const keypair = await solanaWeb3.Keypair;
    let transaction = new solanaWeb3.Transaction();
    let connection = new solanaWeb3.Connection(solanaWeb3.clusterApiUrl("devnet"));

        fromPubkey: keypair.publicKey,
        toPubkey: keypair.publicKey,
        lamports: solanaWeb3.LAMPORTS_PER_SOL,
    solanaWeb3.sendAndConfirmTransaction(connection, transaction, [keypair]);
  } catch (error) {

I've read that Buffer is not available in the latest builds of the web3.js library, but the only answers I've seen are related to Webpack updates. I'm assuming I'm missing a dependency? Any insight is greatly appreciated. Thanks!

1 Answer 1


Buffer is available in Node.js runtimes, but not in browsers.

Without knowing the exact shape of your build system I can only give general advice, which is that you'll need to install a Buffer polyfill like https://github.com/feross/buffer.

We're actively looking to eliminate Buffer from @solana/web3.js completely.

  • I'll give that a shot! What's the timeline on fully eliminating Buffer from the library? Commented Jan 3, 2023 at 16:31
  • 1
    I can't promise anything more than: Stay Tuned™. Commented Jan 9, 2023 at 2:07
  • Circling back to this, I'm not able to find a way to load Buffer using just inline HTML. From what I'm seeing it looks like I would have to use npm or yarn to install the Buffer polyfill. Am I officially stuck until Buffer is removed from @solana/web3.js? Commented Jan 14, 2023 at 18:09
  • You could try some abomination like this, @jeffersonbenson, but really the solution is to build your own polyfill. Relying on others' CDNs is extremely dangerous and can rely on loss of funds. jsbin.com/quzewiticu/1/edit?html,js,console Commented Jan 15, 2023 at 20:47
  • 1
    Good point there @steveluscher. Ultimately I think the answer is there currently is no solution utilizing just the browser bundle to send a transaction to a program. This does kinda shift my project's architecture, but definitely will be helpful in the long run :) Commented Jan 20, 2023 at 15:50

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