Samsung Galaxy S4
The Galaxy S4 will be unveiled March 14. Samsung

Anticipation for the March 14 unveiling of the Samsung Galaxy S4 has been immense but predictable, with a host of mockups, renders and concepts appearing online for a phone that has not yet been seen by the public.

While Samsung remains extremely secretive about the Galaxy S4, engineers and designers have had fun imagining what the next-gen Galaxy S device might look like. We've created a roundup of some of the most popular Galaxy S4 concepts we’ve seen online so far, but with less than a week until Samsung’s Mobile Unpacked event at Radio City Music Hall, there’s still plenty of time for new ideas and concepts to surface between now and March 14.

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Galaxy S4 concept by Rozetked Rozetked

One of the first Samsung Galaxy S4 concepts was brought to us in a video by the guys at Rozetked in late December 2012, which developed a hands-on Galaxy S4 mockup and demonstrated how it worked. Having been in the early stages of Galaxy S4 rumors, many of its suggestions for the phone ranged wildly from a “2.0 Ghz quad 4 quad processor” running Android 5.0 Key Lime Pie, to being thinner than both the Galaxy S3 and the iPhone 5. It's been widely reported that the Galaxy S4 will have either an eight-core Exynos Octa 5 processor or a 1.9 GHz Qualcomm Snapdragon 600 processor (depending on which country you live in) -- but the phone is said to be powered by Android 4.2 Jelly Bean and will likely also be thicker, not thinner, than the Galaxy S3.

The company's video suggested the Galaxy S4 might feature a projection laser keyboard dock that allows users to type without a physical keyboard attachment. This idea has been around since the iPhone 4S pre-release and possibly even earlier, and remains in the realm of fantasy specs.

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Galaxy S4 concept by SamMobile. SamMoible

Also one of the earliest Galaxy S4 concepts is pictured in this January SamMobile rendering. The mockup resembles the Galaxy S3 closely -- save for it being a bit larger (to keep in step with the 4.90-inch screen), and not having a home botton.

It makes sense that concept would use a previous generation phone as a springboard, but Gotta Be Mobile notes Samsung tends to have a lot of tricks up its sleeve that no one anticipates. Several renderings of the Samsung Galaxy S3 surfaced prior to its debut in London last year, yet the actual phone ended up resembling none of them.

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Galaxy S4 concept by Desmond Ma Picasa

This rendering surfaced early on, uploaded onto Picasa in December; it was later discovered by Italian tech site TuttoAndroid. The image was labeled as, “Galaxy S IV GT-I9500 Product Image.” With GT-I9500 being the supposed product name for the Galaxy S4, many toyed with the idea that it could be an actual rendering of the Galaxy S4, noting its likeness to the Galaxy S3, except for it being more rectangular and slightly taller than the predecessor phone.

The validity of the image came into question, however, when enthusiasts realized that the screen featured an already released version of TouchWiz. It then came to light that the mockup was developed by Desmond Ma, a Samsung fan and student from Hong Kong. The image was quickly dismissed thereafter.

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Galaxy S4 concept by Mitchel on The Verge The Verge

This rendering proposed the idea that the Galaxy S4 would be made out of metal. With Samsung being notorious for releasing phones encased in plastic, this would have been an interesting development for the Korean-based company. Later, Samsung officials heavily defended their usual practice, leading us to believe that the Galaxy S4 will too be made of plastic.

The rendering also suggested a host of specs previously not considered, including a 2.0 GHz A15 Exynos S459 quad-core processor, as well as "Corning Gorilla Glass 3," a 3,100 mAh battery instead of the suggested 2,600 mAh battery, and front-facing speakers. The mockup, while impressive and certainly a departure from the norm, was soon determined to be another fan rendering, originally shared on The Verge.

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Possible Galaxy S4 handset shared by SamMobile SamMobile

After sharing its initial rendering of the Galaxy S4, SamMobile returned with something it considered a bit more concrete, but obscure nonetheless. In late February, the tech site shared a photo of a handset with “Samsung Galaxy S4 GT-19500” illuminated on the screen. The device, however, was kept in the shadows, not revealing much of its detail, except for the fact that it’s black and rectangular in shape.

The accompanying specs match those now readily accepted, including a 4.99-inch Full-HD SoLux Display, a Qualcomm Snapdragon 600 processor (suggested for the phone’s U.S. version), storage options ranging from 16 GB to 64 GB of internal memory and a 13-megapixel camera. SamMobile’s rumored specs also include a home button with touch buttons and a plastic back for the phone with aluminum sides, none of which are visible from the image.

Galaxy S4
Samsung Galaxy S4 concept Expansys

One of the most recent renderings for the Galaxy S4 surfaced just days ago: Tech informant @evleaks tweeted an image of a possible Galaxy S4 model alongside images of its predecessors like the Galaxy S3. Accompanying the mockup was spec suggestions of a 4.99-inch screen, a front-facing camera to accompany the 13-megapixel main camera and the implementation of “eye scroll” technology -- one of the Galaxy S4’s most anticipated rumored features.

The mockups were ultimately determined to have originated from French online retailer Expansys, who claims the images were created by its Web designers for the site’s Galaxy S4 pre-sale page. The renderings are considered the most accurate proposed for the Galaxy S4.

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Galaxy S4 concept by Gotta Be Mobile Gotta Be Mobile

Gotta Be Mobile shared its Galaxy S4 concept on March 7, just one week before the smartphone's expected unveiling. In the video, developed by concept designer Martin Hajek among others at the GBM team, the proposed Galaxy S4 is unlike any renderings previously seen: The S4 would be long and sleek, with a removable plastic back -- resembling the Galaxy S3, Galaxy Note 2 and Galaxy Note 8 -- and also borrow from all three handsets, including the S3’s smart stay technology, which Samsung is expected to build upon with eye scroll and eye pause. The video also suggests the Galaxy S4’s suggested front-facing camera will help to power these features.

Despite being a known concept, the GBM rendering is extremely detailed and is compared side-by-side with an iPhone 5, making for the most realistic proposals we’ve seen.

Samsung Galaxy S4 Concepts: Bonus Gallery

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Galaxy S4 concept from Android Pit Android Pit
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Galaxy S4 concept by Rahul Sharma Rahul Sharma
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Galaxy s4 concept by Ben Ling Ben Ling
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Galaxy S4 concept from a Facebook fan page