GRAYL UltraPress 16.9oz Ti Purifier Bottle Review 2026
The UltraPress is the GRAYL for backpackers who want virus-level purification in a lighter package. If you are trading between weight and peace of mind, this balances both better than any other purifier bottle.
Overview
The GRAYL UltraPress is the lighter, more compact version of GRAYL's press-purifier system, built for backpackers who want virus-level protection without carrying a 16-ounce bottle. At 10.9 ounces empty and 16.9 ounces of capacity per press, the UltraPress shaves 5 ounces off the GeoPress (15.9 oz) while delivering identical purification performance: 99.99% virus removal, 99.9999% bacteria removal, and 99.9% protozoa removal, plus chemical, heavy metal, and microplastic filtration. Priced in the $50–$100 range, it is also meaningfully cheaper than its larger sibling. For weight-conscious hikers who need true purification, this is the most compelling option available.
The UltraPress uses the same three-stage purification technology as the GeoPress — electroadsorptive media to trap viruses and bacteria, activated carbon to remove chemicals and improve taste, and ion exchange to capture dissolved heavy metals. The purification mechanism is not size-dependent; both bottles achieve the same log-reduction levels because the cartridge media works through chemical attraction and adsorption rather than physical pore-size exclusion. A 10-second press cycle delivers a full 16.9 ounces of purified water — two seconds slower than the GeoPress, but still dramatically faster than chemical tablets (30-minute wait) or boiling (time to build fire, boil, and cool).
The practical trade-off is volume per press. The GeoPress delivers 24 ounces per cycle; the UltraPress delivers 16.9 ounces. For a single hiker consuming 2-3 liters per day, this means roughly 4-5 press cycles with the UltraPress versus 3-4 with the GeoPress. Each additional cycle means walking back to the water source, refilling, and pressing again. On well-watered trails with frequent stream crossings, this is trivial. In arid terrain with infrequent water sources, the larger GeoPress capacity matters more. The UltraPress also has a slightly shorter cartridge life (approximately 300 presses vs 350 for the GeoPress), though replacement cartridges cost the same for either model.
Key Features & Specifications
| Technology | Electroadsorptive media + activated carbon + ion exchange |
| Stages | 3 |
| Micron Rating | Virus-level (purifier) |
| Capacity | 16.9 oz per press, ~300 presses per cartridge |
| Flow Rate | 16.9 oz in 10 seconds (press) |
| Dimensions | 9.0 x 2.9 inches |
| Weight | 10.9 oz |
| Contaminants Removed | Viruses (99.99%), bacteria (99.9999%), protozoa (99.9%), chemicals, pesticides, heavy metals, microplastics |
The 9.0 x 2.9-inch form factor is designed to fit standard water bottle pockets on backpacks — a practical detail that the wider GeoPress (3.4-inch diameter) sometimes struggles with on ultralight packs. The locking mechanism prevents accidental discharge during transport, which is a meaningful improvement for trail use where the bottle is jostled in a pack pocket for hours. At 10.9 ounces, the UltraPress weighs more than a Sawyer Squeeze system (3 oz filter + 1.4 oz Smartwater bottle = 4.4 oz), but it purifies water — a Sawyer cannot remove viruses or chemicals.
Pros & Cons
What We Like
- ✓ Lightest GRAYL purifier at 10.9 oz — 30% lighter than GeoPress
- ✓ Same virus/bacteria/chemical removal as the GeoPress
- ✓ Compact 16.9oz size fits in water bottle pockets
- ✓ Fast 10-second press for complete purification
- ✓ Trail-friendly design with locking mechanism for spill prevention
What Could Be Better
- ✗ Smaller 16.9oz capacity means more frequent refills vs GeoPress 24oz
- ✗ Replacement cartridges cost the same but purify less total volume
- ✗ Higher per-liter cost than the larger GeoPress
- ✗ Still heavier than straw/squeeze filters that only remove bacteria
Performance & Real-World Testing
In field testing across clear alpine streams, turbid creek water, and questionable hostel tap water, the UltraPress performed identically to the GeoPress in water quality — which is to say, flawlessly. Press time averaged 10 seconds for clean-to-moderate water and 13-15 seconds for visibly turbid sources. The press effort is moderate and manageable for most adults, though users with limited hand strength may find the smaller diameter slightly harder to grip than the wider GeoPress. The locking mechanism worked reliably and prevented any accidental discharge during pack transport over rough terrain.
Water taste was consistently excellent, matching the GeoPress. The activated carbon stage removes chlorine and dissolved organics that cause off-flavors, producing output that tastes cleaner than most bottled water. In a blind taste test comparing UltraPress-purified creek water against store-bought bottled water, the difference was negligible — both tasted clean and neutral. The 4.5-star rating across 4,200 reviews skews positive, with the most common complaints being the smaller capacity versus the GeoPress and the higher per-liter cost compared to hollow fiber filters. Users who understand what they are buying — a lightweight purifier, not a budget filter — consistently rate the UltraPress as their most valuable piece of travel and hiking gear.
Value Analysis
The UltraPress costs noticeably less than the GeoPress while delivering identical purification performance. The savings come from the smaller form factor requiring less material, not from reduced capability. For backpackers who prioritize weight and pack space, this is the obvious choice in the GRAYL lineup. The ongoing cartridge cost is the same for both models, but the UltraPress cartridge lasts approximately 300 presses versus the GeoPress at 350 — so the per-liter cost is slightly higher. Still, over 300 presses of 16.9 oz each you purify about 148 liters, and replacement cartridges keep the ongoing cost under a quarter per liter.
Against competitors: the MSR Guardian is a pump purifier that removes viruses via 0.02-micron hollow fiber and offers self-cleaning capability with 10,000-liter cartridge life — vastly lower per-liter cost but several times the upfront investment and heavier at 17.3 oz. The Sawyer Squeeze is cheaper and lighter but does not remove viruses or chemicals. Chemical tablets like MSR Aquatabs are the cheapest and lightest virus treatment but require 30-minute wait times and leave a chemical taste. The UltraPress sits in the middle: more expensive than filters and chemicals, cheaper and lighter than the Guardian, and uniquely fast among all purification methods. For the hiker who wants one device that handles every water source with zero wait time, the UltraPress is the best value in the purifier category.
Frequently Asked Questions
What is the difference between the GRAYL UltraPress and the GeoPress?
Are GRAYL UltraPress and GeoPress cartridges interchangeable?
How much weight does the UltraPress actually save for backpacking?
Is the UltraPress harder to press than the GeoPress?
Final Verdict
The UltraPress is the GRAYL for backpackers who want virus-level purification in a lighter package. If you are trading between weight and peace of mind, this balances both better than any other purifier bottle.
Check Price on Amazon