When: July 4, 2026 – Pune (India) and Bogotá (Colombia), plus more cities on the tour
Format: In-person, one-day
Ecosystem: Monad
Monad’s traveling one-day hackathon keeps moving through July, with two stops on July 4 alone – Pune and Bogotá – and more cities on the calendar. The format is deliberately compressed: a morning of workshops on Monad’s parallel-execution EVM, a single build sprint to ship a working testnet prototype, then live demos with cash prizes decided by audience vote.
The Monad Foundation team is in the room, which is the real draw – Blitz is the most direct line into the ecosystem’s founders, engineers, and investors. With 40-plus editions shipped since May 2025, from Shanghai to San Francisco, the series is well-oiled and explicitly welcomes Web2 developers trying Monad for the first time. Registration is approval-based, per city, through Luma.
When: July 6–11
Format: Online
The second edition of AMD’s developer hackathon is a build window on AMD’s own AI hardware – Developer Cloud, ROCm, and cloud-accessible AMD GPUs – aimed at AI applications, infrastructure, and raw performance work. The pitch is the absence of CUDA lock-in: a chance to benchmark and ship against AMD’s stack instead of the default toolchain. Hosted on lablab.ai with mentor support throughout, it’s open to all levels, and enrollment is approval-based.
When: July 8–12, 2026 in Ho Chi Minh City
Format: In-person
Pitched as Southeast Asia’s largest on-site AI buildathon: five days in Ho Chi Minh City, 2,000-plus builders, ten enterprise partners, and the full AI stack in one room. GenAI Fund runs it, and the premise is unusual – every challenge comes from a real enterprise partner, and winning projects don’t just take a prize, they enter live deployment and pilot conversations on Demo Day. Problem statements drop July 1, the hackathon itself kicks off on the 11th, and submissions close the 12th, with 60 slots per track on a first-come basis. A strong fit if you want your work to end up in a company’s stack, not on a leaderboard.
When: July 10–12, 2026
Format: In-person – Encode Hub, London
Ecosystem: Arbitrum
The London stop of Arbitrum’s four-city Open House tour, following an 88-team kickoff in New York, and the most founder-shaped event on this list. It’s an application-only, three-day in-person program at Encode Hub for early-stage teams building ventures on Arbitrum: $300,000 in prizes and grants, with direct access to the Arbitrum Foundation, Offchain Labs, Robinhood Chain, AWS, and ecosystem mentors for technical, business, and GTM feedback.
You can apply with an existing project or come ready to start a new one, which is the tell – this is less a weekend hack than a curated room for teams that intend to keep shipping after they leave it. Spots are limited and reviewed for fit, so apply early.
When: July 21–22, 2026
Format: In-person – Toronto, Canada (Blockchain Futurist Conference)
Ecosystem: Ethereum
ETHToronto is the official hackathon of the Blockchain Futurist Conference, Canada’s largest Web3 event, run inside a 40,000-square-foot dome built out for hackers – with conference access included and, yes, the option to sleep on site. Running alongside it, ETHWomen is a free, female-focused and inclusive track open to developers and non-developers from beginner to expert. The hacker portal runs through DoraHacks, with the 2026 application opening via ethtoronto.ca; lock your spot and confirm the build window before you travel. A good fit for a compressed, social, in-person sprint with a full conference attached.
When: July 24–26, 2026
Format: In-person – Lisbon, Portugal (Onchain Lisbon week)
Ecosystem: Ethereum
The marquee open hackathon of the month, and the third flagship on ETHGlobal’s 2026 calendar after Cannes and New York. Thirty-six hours, 600-plus developers, and $125,000+ in prizes across sponsor tracks, with the usual breadth – DeFi, AI + Crypto, Layer 2s, infrastructure, privacy, governance, interoperability. It lands inside Onchain Lisbon week, so the surrounding programming and the density of protocol teams in the city are as much the point as the hackathon itself. Applications run through ethglobal.com; the format is compressed enough that you’re proving an idea has legs, not shipping a finished protocol.
Tracking Web3 Hackathons Worldwide
The shape of July is hard to miss: five of the seven hackathons that start this month are ones you attend in person. Monad’s one-day Blitz, Agentic AI Build Week in Ho Chi Minh City, Arbitrum’s Founder House, ETHToronto, and ETHGlobal Lisbon all put builders in the same room as the people who run the chains and the companies hiring them. The two Web3 flagships land back-to-back – Toronto on the 21st, Lisbon on the 24th – and the only online entry is AMD’s GPU week.
July trades volume for proximity – fewer marathons, more rooms. Explore the full interactive hackathon calendar on Web3Voyager, filtered by ecosystem, format, and location. Running a hackathon, or know one we missed? Submit it here and we’ll get it in front of thousands of active builders.
