The Inogen One G5 vs. The Inogen One G4: Which One is Best for You?

The Inogen One G5 vs. The Inogen One G4: Which One is Best for You?

If you’ve been tuning into our blog the last couple weeks, you probably read our post comparing the Inogen G5 and the Inogen G3. In this post, we showed you some of the key differences between the units that you may not have known such as their size, weight, and battery life.


While the G5 and G3 are widely considered to be the best portable oxygen concentrators on the market, they are far from your only options. There are a host of high-quality portable oxygen concentrators by Inogen, Philips Respironics, SeQual, and more that have broken boundaries in the oxygen therapy field.


So, in an effort to better inform buyers about their options, we make it a priority to give each portable oxygen concentrator its fair share of time and shine a spotlight on the unique features of each device. In this post, we’re going to compare the Inogen One G5 portable oxygen concentrator and the Inogen One G4 portable oxygen concentrator.


If you have any questions about what you read here, feel free to leave them in the comment section below or get in touch with one of our respiratory specialists. They will be able to walk you through your options and respond to any questions or concerns you may have about Inogen portable oxygen concentrators.


Inogen One G4 Overview

The Inogen One G4 was released in 2016 to the U.S. market. At this time, it produced more oxygen per pound than any other portable unit and was praised for allowing COPD patients around the world to regain their freedom and independence.


The Inogen One G4 adapted a new design over the G3 which opted for a more sleek and minimalist look. Instead of the sieve beds being visible on the outside of the unit like with the G3, they’re embedded in the front of the unit in one single column. 

Inogen One G4


Another welcome addition to the G4 was its connectivity. The new Inogen Connect app allowed users to interact with their portable oxygen concentrator via their smartphone or tablet. This app allows people to see their battery life, column condition, and other information without ever having to look at their G4 control panel.


Inogen One G5 Overview

Releasing in the summer of 2019, the Inogen One G5 is the latest and greatest portable oxygen concentrator available from Inogen. Aside from a few minor changes, the look of the G5 remained mostly untouched from the Inogen One G4.  

Inogen One G5


The most notable improvement with the G5 is that it doubled the oxygen output of the G4. This expanded pulse dose technology significantly and allowed more people to benefit from ultra-lightweight portable oxygen concentrators.






For many people, weight is the single most important factor when it comes to portable oxygen concentrators. With a light portable oxygen concentrator, you’ll be able to go where you want and do what you please without being overburdened or becoming breathless after a few minutes of walking. 


Both the Inogen One G5 and the Inogen One G4 are pulse flow concentrators. What this means is that oxygen is only delivered when the patient inhales as opposed to continuous flow where oxygen is put out persistently. Using this technology, oxygen concentrator manufacturers are able to make smaller devices that still provide you with a reliable source of oxygen.


Man and woman standing with portable oxygen concentrator

One of the major selling points for the Inogen One G4 is that it’s the lightest Inogen concentrator ever produced. The only concentrator that has it beat in this category is the AirSep Focus which has less oxygen output and shorter battery life. The Inogen G4 weighs in at just 4 pounds with the single battery which is a half-pound lighter than the G5.


Oxygen Output

Oxygen output is probably the most objective aspect of oxygen concentrators; you’re either getting the oxygen you need to stay healthy, or you need a device that puts out more oxygen. If you need to be on a flow setting of 3 or higher, then the G5 will always be a better unit for you because the G4 only goes up to a setting of 3.


Conversely, if you are in the early stages of COPD and see no reason to have a device that goes up to a setting of 6, then the G3 may be perfect for you. Another thing to note about oxygen output is because the G4 is so light you may not need as much oxygen to feel normal. However, before adjusting your flow setting you need to first speak with your pulmonologist.


One thing you need to take into consideration when deciding between the G5 and G4 is whether or not you will be moving to a higher flow rating anytime in the future. If you already use a setting of 3 and your doctor predicts you may need to move up soon, it would be wise to invest in a unit that can go higher than that.



Size is one factor that you may find important when purchasing a portable oxygen concentrator. Large portable oxygen concentrators and oxygen tanks are not only heavy, but they tend to have awkward shapes as well. For example, oxygen tanks are long and have nozzles on the end that tend to get caught on things like clothing. This makes it difficult to store it anywhere without worrying about it getting damaged.


The G4 and G5, on the other hand, are designed in a way that makes them very easy to carry and store. They’re more box-shaped than many portable oxygen concentrators on the market meaning they don’t take up any more space than they have to. There isn’t anything that protrudes from the device either so you won’t have to worry about it getting caught on anything.


Inogen One G4 portable oxygen concentrator


In terms of the actual dimensions, the G4 and G5 are pretty similar, however, the G4 is the lighter of the two units. The G4 is 7.2” H x 5.91” L x 2.68” W and the G5 is 8.15" H x 7.19" L x 3.26" W. That’s not a huge difference, but if you’re looking for the smallest unit possible, the Inogen One G4 is a great machine to go with.


Sound Level

People often come to us and express the concern that their oxygen concentrator will be too loud and that they’re worried about taking it places because it may disturb people. Fortunately, most concentrators on the market are pretty quiet, even continuous flow units, and shouldn’t be a cause for concern. 


The Inogen One G5 rings in at just 38 decibels while the G4 is just two higher than that at 40 decibels on a flow setting of two. Either way, that’s about the sound level of a whisper or a quiet conversation. 


Oxygen concentrator sound


Another thing to take note of is the audible alert system that’s built into both the G4 and the G5. The audible alerts will notify you when your battery is low or if certain parts need replacement. If you are in a public area, you may want to disable this and re-enable it once you’re back home because the alerts may be louder than the actual concentrator.


Battery Life

Because portable oxygen concentrators cannot be plugged into the wall at all times like a home oxygen concentrator, they need a power source to draw from. The quality and longevity of your batteries are important because you don’t want to be out of the house without a way to power your portable oxygen concentrator.


Within the past couple of years, Inogen has put a lot of work into making their batteries more lightweight, efficient, and reliable. The Inogen One G5 double battery can go up to an astounding 13 hours on one charge with a flow setting of 1. That’s a steep incline from the G4’s maximum battery life of just 5 hours on a setting of 1.


Oxygen concentrator battery life


FAA Approved

Part of regaining your freedom and independence means being able to fly on a plane again without hassle. Fortunately, you can rest easy knowing that both the Inogen One G5 and the Inogen One G4 are approved by the Federal Aviation Administration (FAA). What this means is that you’ll be able to bring your oxygen concentrator onto the plane as a carry-on item no matter where you are in the world. Due to the size and weight of the G4, you’ll have more options when it comes to storing your device while in flight.


Federal Aviation Administration (FAA)


One thing that’s unique to both the Inogen One G4 and Inogen One G5 is their connectivity. Whenever you purchase one of these devices, you will have access to a free smartphone application that connects to your portable oxygen concentrator. This app is called Inogen Connect.


Inogen Connect App

Using the Inogen Connect app, you will be able to get important updates about your POC without ever having to look at it. Below is some of the information you will see:

  • Battery status
  • Software updates
  • cannula and filter maintenance updates
  • Column life
  • Troubleshooting tips, FAQS, and the user manual
  • Oxygen purity status

There’s no understating how convenient it is to have Inogen Connect. Unlike with other portable oxygen concentrators on the market, you’ll never have to take your user manual with you or remove the device from its carrying case to check its battery status or view other important information.

G4 and G5 Side-by-Side Comparison


Inogen One G5Inogen One G5

inogen-one-g4-portable-oxygen-concentrator_418x418-removebg-previewInogen One G4

Oxygen Settings

Pulse Dose: 1 to 6

Pulse Dose: 1 to 3


4.7 Pounds

2.8 Pounds

Battery Duration

Up to 6.5 hours with single battery

Up to 13 hours with double battery

Up to 2.7 hours with single battery

Up to 5 hours with double battery

Battery Charge Time

Up to 4.5 hours with single battery

Up to 9 hours with double battery

Up to 3 hours with single battery

Up to 5 hours with double battery

Maximum Oxygen Output

1260 ml/min

630 ml/min

Noise level

Around 38 decibels

Around 40 decibels


Width: 7.19 inches

Depth: 3.26 inches

Height: 8.15 inches

Width: 5.91 inches

Depth: 2.68 inches

Height: 7.2 inches


Who Should Buy the Inogen One G4? 

The Inogen One G4 is a fantastic portable oxygen machine that’s still the second lightest unit on the market, despite it being several years old. The best candidate for the Inogen One G4 is someone who wants a lightweight and small form factor concentrator that’s backed by a reputable and reliable brand like Inogen. However, be aware that it only goes up to a pulse flow setting of 3.


While the Inogen G4 is not the newest oxygen concentrator by Inogen, it remains a popular unit among COPD patients all over the world. Due to the high demand for the G4 Inogen still supports it by selling batteries, accessories, and replacement parts. Patients looking to buy a G4 will be happy to find that Inogen will support the device for years to come.


Who Should Buy the Inogen One G5?

The Inogen One G5 is the fifth generation of portable oxygen concentrators by Inogen. It’s the most advanced unit they offer with an impeccable battery life, lightweight design, and high oxygen output. The ideal candidate for the G5 is someone who wants the best battery life and highest oxygen output possible for a pulse flow unit.


Since the Inogen One G5 is the newest device by Inogen, you will always be able to find technical support if you need it. Most oxygen retailers sell this unit and many of them will repair it or send you replacement parts if you need it. Currently, the G5 offers the highest oxygen output of any pulse flow unit and the longest battery life.  



As you can see, both the Inogen One G4 and the Inogen One G5 are viable portable oxygen concentrators. While the G5 is still the most advanced oxygen concentrator on the market, the G4 still has a lot to offer if you want an extremely small and lightweight unit. At the end of the day, it’s a matter of what your oxygen demands and preferences are.


Personally, we love the Inogen One G5 because it’s proficient or excels at everything it does including battery life, weight, size, oxygen output, and more. As such, we gave it the title, “the best portable oxygen concentrator of 2020.” If you’re still not sure which oxygen concentrator is right for you, be sure to get in touch with us and we’ll walk you through your options.

Leave a comment

Your email address will not be published. Required fields are marked *

Please note, comments must be approved before they are published