A Complete Guide to the OpenSea NFT Marketplace
When NFTs boomed in 2021, one NFT marketplace was king. Now that another NFT boom is here, could that same marketplace return to the top of the mountain? We’re talking about – of course – the OpenSea NFT marketplace.
OpenSea has played a big role in NFTs entering mainstream consciousness, and was – and for many still is – the NFT marketplace of choice for millions of NFT traders around the world. Today, it faces more competition than ever before – and with NFTs on the rise once again, OpenSea has a lot of ground to gain to get back to the top.
Here’s our complete 2025 guide to OpenSea.
Key Insights
Created by Devin Finzer and Alex AtallahDebuted in December 2017The world’s biggest NFT marketplace during the 2021 NFT boomFacilitated over $39.5 billion USD in NFT trades (as of December 2024)Currently the third most popular NFT marketplace, after Magic Eden and Blur (as of December 2024)
What is OpenSea?
OpenSea is an NFT marketplace that supports Ethereum-based blockchains. With OpenSea, users can create, buy, and sell a wide variety of NFTs, including digital art, collectibles, virtual land, and more.
Created by Devin Finzer and Alex Atallah, OpenSea took advantage of growing interest in NFTs in the latter half of the 2010s to become the #1 NFT marketplace in the world when NFTs had their first boom in 2021.
With OpenSea, users can perform many types of NFT transactions, including:
Primary sales: the debut sale of a new NFT, via the OpenSea launchpadSecondary sales: existing NFTs that are listed at a set price by their holderNFT auctions: NFT holders can hold an auction for the assets they’d like to sellNFT offers: potential NFT buyers can propose a price to purchase an NFT, even if it is not listed for sale
OpenSea uses highly-developed smart contracts to ensure that transactions are smooth, secure and transparent. Users can connect many of the most popular software wallets to the platform – including MetaMask, Coinbase Wallet and more – to view and interact with NFTs across the site.
The OpenSea NFT marketplace is well-known as a go-to location for trading the biggest NFT collections, including CryptoPunks, Bored Ape Yacht Club, Pudgy Penguins and more. OpenSea also supports many smaller collections and projects, making it an pleasing platform for both NFT creators and NFT collectors.
The history of OpenSea
OpenSea began with the success of CryptoKitties – a blockchain game developed by Dapper Labs that debuted in 2017. With its success, Finzer and Atallah recognised the potential of NFTs, and so they set out to build an NFT marketplace that could support these fast-growing assets.
The OpenSea NFT marketplace went live in December 2017, and quickly grew a fanbase off the back of its user-friendly design – one of the first NFT marketplaces out there that was designed from the ground-up to be as approachable for beginners as possible.
OpenSea quickly rose to become the #1 NFT marketplace, even though trading volumes were rather modest to begin with. This changed in 2021, when the explosion of NFTs saw trading volumes reach billions of dollars in just a few months, putting OpenSea at the very heart of the NFT industry.
The OpenSea capitalised on this success in successive funding rounds. They raised $100 million USD in July 2021, and a further $300 million USD in January 2022, which took the valuation of OpenSea to a incredible $13.3 billion USD.
Midway through 2022, NFTs saw a decline in popular interest. Despite this, OpenSea used the funds generated over the past 12 months to expand. In April 2022, OpenSea acquired the trader-focused NFT marketplace Gem, relaunching it as OpenSea Pro in April 2023.
OpenSea faced its first major competitor in October 2022, with the debut of NFT marketplace Blur. OpenSea quickly saw Blur take its crown as the #1 NFT marketplace, with its detail-focused user interface and an upcoming token launch enticing many users to switch across.
2023 and 2024 have seen further challenges to OpenSea, with the surge in popularity of NFTs on Solana – a blockchain OpenSea does not support – helping Magic Eden rise to become the new #1 NFT marketplace in the world.
Despite all of its success, OpenSea has also been through a number of controversies. In its early days, OpenSea struggled to both detect and prevent sales of NFTs with plagiarised artwork, or that were outright stolen. Thankfully, numerous security developments and platform updates over the years have helped to largely mitigate both of these issues.
OpenSea has also been met with backlash for its back-and-forth stance on supporting creator royalties. Their wavering stance on this topic was one of the major reasons behind the rise in popularity of rival NFT marketplace such as Blur and Magic Eden.
As we enter 2025, many deem OpenSea to be the third most popular NFT marketplace, coming in behind both Magic Eden and Blur. With NFT interest picking up once again however, there’s plenty of opportunities for the order to shake up once again in the year ahead.
What’s next for OpenSea?
Today, OpenSea finds itself in an interesting position.
In recent months, rumours have been circulating that OpenSea is finally preparing to debut its own token. This would allow it to catch up with its rivals – with two of the biggest, Blur and Magic Eden, having already launched their ecosystem tokens in $BLUR and $ME.
November 2024 saw OpenSea tease a revamp of their whole NFT marketplace experience, with this new site set to arrive in December 2024. For those with access to private tests, the feedback has been positive – but it remains to be seen if this can transform OpenSea’s fortunes and take them back to the summit of the NFT industry.
In the NFT boom of 2021, OpenSea was in the right place at the right time to capitalise. This time around, OpenSea starts the race a few lengths behind. With their history and experience however – and of course with the revamped marketplace experience on the way – 2025 could see massive changes in the sites we use to buy, sell and trade NFTs once again.
