testing for SlingFin Portal 3 review

SlingFin Portal 3 Review

A premium 3-person, all-season backpacking tent

November 3, 2023 –  The SlingFin Portal 3 Tent is large, livable, relatively lightweight, well-featured, and slots into a category we refer to as “all-season” or “3+ season.” That is, thanks to SlingFin’s impeccable engineering, it is far sturdier and more storm-worthy than your average 3-season tent, but not specifically designed as a winter/4-season model. And within that genre, it is our preferred 3p tent for backpacking. Shop now.

You may also be interested in our SlingFin Portal 2 Review.

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  • Price: $600
  • Weight: 3 lbs, 12 oz
  • Material: Fly: 10D Sil/Sil Ripstop Nylon. Floor: 20D Body Nylon Ripstop PE. Body: 15D nylon
  • Interior: 41.5 ft² | Vestibule: 20.6 ft² | Area/Pound: 16.5 ft²
  • Length: 92″ Width: 68″/62″ tapering Height: 44″
  • Pros: Strong and storm-worthy. Spacious. Relatively lightweight. Freestanding. Good headroom. Easy Setup. Many internal pockets. Vents.
  • Cons: Expensive. Not ultralight. Unusual tensioning hardwear.
looking inside the portal 3

Construction & Features

In SlingFin’s own words, “this tent is more than a scaled up version of our Portal 2.” Because it has a larger wind profile and snow-loading potential, they’ve given it heavier duty poles (upgraded from 8.7mm DAC NFL to 9.3mm DAC NFL) to bear additional force. The top spreader bar adds ceiling space, and was upgraded from 9.3mm on the 2P version to 10.65 on the 3p version.

A bevy of engineering-centric enhancements further stabilize this tent against strong wind and snow. This includes internal guylines at the head end, which reduce lateral torsion, the outrigger pole attachment which adds stability and protects against snow-loading, and numerous guy-out points to buffer the windward side (extra guy-out lines and stakes come complimentary)

One thing we love about all SlingFin tents, including the SlingFin Portal 3, is their use of sil/sil fly fabric. That is, the fly is treated with silicone on both the exterior and interior side, instead of Sil/PU or Sil/PE. Double Sil increases the waterproofness, strength, UV-resistance, and overall lifespan of the fabrics and helps prevent hydrolysis (the smell of old tent decay).

On the inside, you will find a wide array of mesh storage pockets, placed on the side and overhead, so your gear will be well-organized. A few more features we like include the kickstand fly-vents, and the inclusion of spare zipper sliders should one ever fail.

Lastly we have a few very minor downsides to call out. SlingFin uses clam-cleat styling tensioning for the fly, which has a great hold, but can be weird and confusing to new users. The provided stakes don’t come with pull-loops, and thus are harder to get out of the ground and don’t have reflectivity. There is no tensioning on the tent body’s corners, so you must achieve tension as you stake the loops, rather than pulling cords after pounding in the stakes. And finally, we’ve been growing accustom to magnetic door-roll-ups on ultralight tents at this price point, and find that traditional toggles are now a step behind the curve.

tent body and mesh bug protection


SlingFin Portal 3 Footprint

6.9 oz | $95

Extend the lifespan of your floor and increase weather resistance by adding the Portal 3 Footprint. Made with PE-coated 20d ripstop nylon, this ground cloth exactly matches Portal 3’s profile. It attaches to pole tips and can become the floor in a fly-only mode pitch.

SlinFin Portal 3 Tub Floor

9.5 oz | $135

This is a standalone bathtub floor that replaces the traditional tent body for a dedicated fly-only pitch for use in non-buggy conditions. It has sidewalls, and is made with 20d Nylon Ripstop PE.

SeamGrip+SIL Seam Sealant


By default, purchasing Portal 3 comes with a pro seam sealing service. However, you can save $20 by purchasing this seam sealant and doing it yourself. Specifically, you have to use THIS type of sealant, as traditional offerings won’t stick to the Sil/Sil fabric. We don’t recommend bothering with this, because it’s both time consuming and space-intensive, and you won’t do as good of a job.

interior view of portal 3

When You Should Choose SlingFin Portal 3

We recommend backpackers choose the SlingFin Portal 3 for any of the following reasons:

  • You frequently camp in windy climates and in unprotected sites
  • You value the optionality of being able to very comfortably sleep two, or cozy up to sleep three
  • You and your partner both use wide sleeping pads
  • You will frequently sleep three smaller-than-average-sized adults, or two full size adults plus a child or large dog
  • You already own a 2P tent
  • You appreciate good engineering and well-designed lightweight gear
  • You want a versatile, durable tent that will last a long time if well taken care of
view inside the tent

When You Should Choose A Different Tent

  • You don’t care about going ultralight and reducing your base weight to the bare minimum with a trekking pole shelter. Portal 3 is light-not-ultralight
  • You are on a budget – $600 ain’t cheap.
  • You want a tent you can also use solo
    • It’s not that you can’t use SlingFin Portral 3 solo, but the footprint is large and you’ll always be carrying extra weight so we strongly recommend against that
  • You intend to use it primarily to sleep three medium or larger sized adults
    • In which case, choose a 4p tent, or split into two smaller tents. This is not a flaw specific to Portal 3, all 3P tents feel cramped when used by three full size adults at max capacity
SlingFin Portal 3

SlingFin Portal 3 Review Verdict

Just like it’s smaller siblings, the SlingFin Portal 3 is the sturdiest lightweight tent in its capacity-class. As such, it won the “Most Bomber” award in our guide to 3 person backpacking tents. The design is smart, very storm-worthy, highly livable, durable, and ready for many a good night in the backcountry. The bottom line is that SlingFin makes great tents for backpacking, and Portal 3 is no exception.

tent at sunrise