In today’s article, Jeremy Tremp reviews the GOYOJO GRL335 thermal optic. This 4x optical scope offers an attractive price point with a professional-grade sensor and easy operation. How does it perform? That’s what Tremp sets out to discover. The optic was provided by GOYOJO Optics for the review.
There is a moment in every shooter’s life when technology catches up with imagination.
For many of us, when we think of thermal vision we immediately picture those old 80s action movies like Predator, or more modern video games. But in this day and age owning such technology for ourselves is becoming more and more commonplace, as well as affordable.
When the GOYOJO GRL335 arrived at my door, it marked my first step into that world. And mounting it atop my Springfield Armory Heatseeker felt like the perfect way to experience thermal for the first time.
This was not just a new optic. It was a new way to see.
The Details of the GRL335
Opening the box, I expected something fragile and overly technical. Thermal optics still feels like advanced gear, even if prices have become more approachable. Instead, the GRL335 presented itself as compact, sturdy and dense — dense in the sense that you are holding something of value, something made with care and precision.
The housing is built from an aluminum-magnesium alloy, which keeps the optic strong and protected, while also shedding weight. At 19.5 oz. without the battery, it’s not going to add too much heft to your rifle. For reference, my Nightforce 4-20 ATACR weighs 35 oz. On the Heatseeker’s bolt gun profile, it still feels well within the rifle’s natural balance and handling compared to a traditional daytime optic.
The included 18650 rechargeable lithium battery is installed under a quick-detach cap. Its six to eight hours of runtime is respectable, but the ability to swap batteries quickly in the field is what matters to hunters who stay out after dark. It’s always nice to have the confidence to keep your gear up and running with spare batteries.
Fit and finish exceeded what I expected in a “best budget 384×288” category optic. Buttons feel positive and deliberate. Nothing rattles. The IP65 rating gives confidence against dust and rain, which is not theoretical for hog hunters who sit through humidity and unpredictable weather.
The Picatinny mount interface is straightforward, and the latch is well-designed. It gives confidence that the optic will not budge once affixed into place on your rifle.
The GRL335 features a 35mm objective lens with a 4X optical base magnification. That starting magnification feels right on a bolt gun. It provides enough detail for identification while keeping the field of view workable to see what is around your target, especially when using this optic to spot your varmints during a hunt. Eye relief sits at 50mm, and diopter adjustment ranges from -5 to +5.
Hands-On with the GOYOJO GRL335
Getting behind the optic was simple. Within minutes, the image snapped into clarity. The GRL335 worked great with my eye right in the cup or backed out 6+ inches. Depending on your rifle, you may not always be able to get the optic right up to your eye.
The GRL335 uses a 384×288 vanadium oxide uncooled infrared focal plane array sensor with a 12μm pixel size and a NETD of less than 25mK. Now if that sounds like space wizard magic, to me it is. To a thermal aficionado who understood that sentence, I applaud you. Basically, in practical terms, that means it detects extremely small temperature differences.
The 1024×768 OLED display renders a crisp, highly detailed image. The frame rate tops out at 55Hz, which keeps motion smooth and less jarring than other budget optics. Panning across a field does not produce the stutter that can induce eye fatigue. For reference, a typical TV displays at about 60Hz.
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For a first-time thermal user, the intuitive button layout is a major advantage. The menu system is straightforward. No endless submenus or weird abbreviations. Within a short time, I was cycling through the five image modes and testing digital zoom settings at 1x, 2x, 3x, and 4x. It’s all really quite intuitive and user-friendly for new adopters like myself.
This was another aspect that I was pleasantly surprised by. Oftentimes, thermal optic menus are endlessly complicated or difficult to navigate. This optic felt like it was designed by people who actually understand designing a product for a real-world user.
In the View Of…
The GRL335’s Classic One Shot Zero and Thermal One-Shot Zero features make zeroing this optic incredibly easy. The process is simple. Fire a single round, freeze the image, and move the reticle to your point of impact. Done.
On the Heatseeker, zeroing felt no more complicated than adjusting a traditional scope. In fact, in some ways it felt easier. For a consumer entering thermal for the first time, this feature alone lowers the barrier significantly.
The PIP, or picture-in-picture, feature was also really cool. Rather than simply magnifying the entire field, the GRL335 allows a separate zoomed window within the main image. That means you retain situational awareness while refining your aiming point. For hog hunters engaging multiple animals or scanning for movement, this matters.
On a bolt gun like the Model 2020 Heatseeker where deliberate shot placement is the norm, the PIP function complements the rifle’s personality. It feels like a precision tool, not a novelty feature.
The GRL335’s 35mm objective lens extends detection to approximately 1,800 meters under ideal conditions. That number is impressive, but realistic expectations are important.
Detection does not equal identification.
In practical field use, identification distances will be shorter and dependent on environmental conditions. Humidity, vegetation density, and ambient temperature all influence performance. That said, even at conservative distances, the optic opens capabilities that traditional glass simply cannot match in darkness or low light.
For varmint hunters targeting coyotes across open pasture or hog hunters watching feeder lines at night, the ability to detect heat at significant range changes strategy. Instead of waiting for sound or movement in the dark, you see presence first. Super cool.
Rated to withstand up to 1000g of recoil impulse, the GRL335 is robust enough for centerfire bolt guns. On the Heatseeker, recoil posed no issue during my testing.
Operating temperature range spans from -20°C to 50°C. For predator hunters in winter and hog hunters in Southern heat, that versatility matters.
Recoil Activated Video, or RAV, is a feature I did not realize I wanted until I had it. You may not always be immediately ready to record, and you also don’t want to record so much that you fill up the SD card before you even spot your prey.
The optic includes 64GB of onboard storage and Wi-Fi connectivity for app integration. When a shot breaks, the system captures the moment automatically. For hunters who enjoy reviewing shot placement or sharing experiences with friends, this is a non-negotiable feature.
Final Thoughts on the GRL335 Thermal Optic
Thermal is not a replacement for traditional optics. It is a tool for specific use-cases.
For hog hunters dealing with nocturnal patterns, the GRL335 transforms the night from a guessing game into a calculated environment. You can scan fields, identify heat signatures moving along tree lines, and plan your approach or position accordingly.
For varmint hunters targeting coyotes, thermal allows detection before the animal commits fully into a call set-up. Instead of reacting to a sudden appearance, you track movement as it develops. Receiving my first thermal optic felt like stepping into the future of hunting — state regulations permitting, of course.
The combination of a professional-grade 384×288 sensor, intuitive controls, strong battery life, and durable construction makes it approachable for first-time thermal users while offering serious performance.
On the Springfield Armory Model 2020 Heatseeker, it complements a rifle designed for modern predator work. The experience reshapes how you think about darkness. Night is no longer an obstacle. It is simply another environment.
For those considering their first thermal optic, the GRL335 proves that advanced capability no longer lives only in high-dollar gear. It is accessible, practical, and ready for the field. Current pricing is $949.
The first time you watch a distant heat signature materialize in a pitch-black field, you realize something important. You are not just looking through an optic. You are seeing the world differently.
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