Web3 hackathon demo video: how to show the wallet step cleanly

Judges usually meet your project through a two to four minute video before anyone opens the repository. Here is what the big web3 hackathons ask for, a three-minute script that fits their rules, and how to handle the moment almost every web3 demo has: the user's wallet on screen.

Published: 17 October 2026

What judges see first

At most hackathons, the demo video is the project. Judges work through dozens or hundreds of submissions, and Devpost, which hosts many of them, calls the video one of the first things judges look at. The advice it collected from past participants comes down to one line: make sure it is a demo, with the project shown in action rather than a slide deck. The video is also public by design: Devpost asks for a YouTube, Vimeo or Youku link with privacy settings that let anyone watch it.

Web3 events add their own rules, and they are strict. Here is what two of the largest ask for.

ETHGlobal scores projects on five criteria: technicality, originality, practicality, usability and a "wow factor". It also warns that submissions with large single commits or missing histories may be disqualified. Read together, the rules send one message: judges reward working code they can trace, explained by a human voice.

A three-minute script that fits the rules

Three minutes is enough if every second has a job. Write the script well before the deadline, as Devpost's contributors advise, and time it out loud.

Two habits help. Drive the live part with real input, because a demo whose numbers never change reads as a mockup. And keep the explorer tab ready: a deployed contract address that judges can open is the fastest proof that the on-chain part exists.

Show the signing step, do not skip it

Usability is one of the five criteria, and in web3 the wallet prompt is part of the user experience. Let the signature or transaction request stay on screen long enough to read, say in one sentence what the user is approving, then show the result: the updated state in your app and the confirmed transaction on the explorer. If the testnet is slow, cut the wait in the edit rather than speeding it up, which the rules forbid. A demo that hides every prompt behind a jump cut leaves judges wondering whether the on-chain part works at all.

The wallet problem every web3 demo has

Almost every web3 project has a moment where the user's wallet appears: connect, sign, approve, receive. Teams reach for whatever wallet is open in their browser, and that is where the trouble starts. There are three candidates, and each has a flaw.

• Your personal wallet. The video is public, and any viewer can pause on the address and look it up. On Ethereum and other EVM networks an account keeps the same address everywhere, as MetaMask's help center explains, so a testnet session in your main account still shows your mainnet address, with its holdings and history.
• The testnet wallet you used all weekend. Safe, but odd on screen: a few faucet drips, leftover test tokens from other projects, names like SepoliaETH. Faucets ration supply: Alchemy's Sepolia faucet gives 0.1 ETH once every 24 hours, and only to an address holding at least 0.001 ETH on mainnet. That condition is exactly what pushes people to request test ETH with their main address.
• A brand-new wallet. Clean, but empty. A zero balance tells no story, so the "before" of your pitch is missing.

A real wallet in a public video is not a small risk. Why showing crypto online makes you a target sets out what security firms advise people who appear on camera, and screen sharing a wallet on a call covers the live pitch version of the same problem.

Set up a demo wallet before you record

1. Create a new account for the demo, from a new recovery phrase. Never import your personal phrase into a demo browser.
2. Fund it on the testnet your contracts use. Ethereum.org names Sepolia the recommended default testnet for application development; Holesky has been deprecated since September 2025.
3. Name the account "Demo" and hide stray test tokens, so the token list shows only what your project uses.
4. Record in a clean browser profile: no bookmarks bar, no other extensions, no tabs signed in to personal accounts.
5. Turn notifications off, and record on the computer: ETHGlobal does not accept phone recordings.
6. Export at 1080p, never below 720p, and never speed footage up to fit the limit. Cut instead.
7. Watch the final file frame by frame for an address, an email or a document you did not mean to show.

The recording side, from resolution to cursor movement, is covered in recording a wallet screen video.

Story frames and the working demo are different things

Look again at the first twenty seconds of the script. Before the live demo, a good pitch shows the user's situation: a wallet holding some stablecoins and a little ETH, for example, which your app is about to put to work. At the end, it may show the same wallet after. These are story frames, not the product. A testnet wallet showing 0.0731 SepoliaETH and three tokens from someone else's project makes them confusing; your personal wallet makes them dangerous.

For those frames, some teams use a different kind of tool.

A larp wallet, also called a crypto wallet app simulator, is an app that shows a believable crypto wallet screen built from the balances you type in, for videos, skits, pitch decks and demos. It holds no funds and touches no blockchain.

You type the balances the story needs, say 1,250 USDC and 0.8 ETH, and capture the screen. Nothing in the frame leads to an address or a history. We make one of these apps, My Larp Wallet; what a crypto wallet simulator is explains what the category does and where it stops.

The rule that keeps this honest: story frames illustrate the user, and everything that shows what you built is your project, running on testnet, recorded live. Judges score technicality and practicality, so they want to watch real code do real things. If your project outlives the weekend, app demo videos for crypto products applies the same split to launch and investor videos.

Where the line is

A simulated wallet frame is an illustration. Put a small "Illustration" label on it, keep it out of the live demo segment, and never use it to show a feature you did not build, a transaction that did not happen, or traction such as deposits or users. A mockup proves nothing about anyone's holdings or about your code. Presenting it as real holdings, real traction or evidence of any kind is deception, and our terms of use forbid it.

Sources

• ETHGlobal, ETHOnline 2026 event details: submission, demo video and judging rules, 2026
• Colosseum, Perfecting your hackathon submission, May 8, 2025
• Devpost, 6 tips for making a winning hackathon demo video
• Devpost Help Center, Uploading a demo video, September 25, 2026
• ethereum.org, Networks (testnets and faucets), September 23, 2026
• Alchemy, Ethereum Sepolia faucet, 2026
• MetaMask Support, The Ethereum address format and why it matters

Questions

How long should a hackathon demo video be?

Check the event rules first, because some platforms enforce them on upload. ETHOnline 2026 required a video between 2 and 4 minutes and rejected anything outside that range. Colosseum asks for a pitch video of no more than three minutes plus a separate technical demo of 2 to 3 minutes. Within the limit, put the core of the demo in the first two to three minutes.

What should a hackathon demo video include?

The problem in one user's words, what you built in one sentence, the project running with real input, a short look under the hood such as the deployed contract on a block explorer, and what comes next. Devpost's advice from past participants is to make it a demo, showing the project in action rather than a slide deck.

How do I prepare for a hackathon demo?

Write and time the script before the final night, set up a dedicated demo wallet funded on the testnet your contracts use, record in a clean browser profile with notifications off, and keep a backup take. Then watch the export frame by frame for an address, an email or a document you did not mean to show.

Can I use mockups in a hackathon demo video?

For context frames, such as the user's wallet before your app does anything, a clearly labeled mockup is fine. For anything that shows what you built, no: judges score technicality and practicality, and ETHGlobal warns that submissions with large single commits or missing histories may be disqualified. The working part must be real and recorded live.

Should I use my own wallet in a hackathon demo?

No. Hackathon videos are public, and anyone can pause on the address and look it up. On Ethereum and other EVM networks an account has the same address everywhere, so a testnet session in your main account still exposes your mainnet address, its holdings and its history. Create a separate wallet for demos.