Osaki OS-4000 Executive Zero Gravity Massage Chair Review

by Mary Lou | Last Updated: April 24, 2016 When you buy something using the links on our posts, we may earn a small commission at no additional cost to you. Learn more.

Looking for inside intel on the Osaki OS-4000 massage chair? You’ve come to the right place. We’ve got a lot to say about its size, features, ease of assembly, and that darn user manual.

Executive Summary

The Osaki OS-4000 Executive Zero Gravity Massage Chair Recliner Deluxe is a relatively affordable massage chair with zero gravity and a decent massage. However, there are newer and better contenders with similar price points. The product claims that it can fit all users up to 6’4”. But if you are broad-shouldered or are taller than six feet you might actually be unable to fully enjoy the chair’s benefits – or even fit into it.

Other causes for concern are trouble with the after sales support in the past months and the chair’s controls – which some find to be difficult to use.

If this sounds troubling, you’re better off getting another massage chair without these issues. If you’ve still got your heart set on an Osaki, go for the Osaki OS-4000T instead. The model T is an updated version with added foot rollers and improved chair covering.

Osaki OS-4000, 1 Count (Pack of 2), Taupe
31 Ratings
Osaki OS-4000, 1 Count (Pack of 2), Taupe
  • ZERO-GRAVITY MASSAGER: Zero-gravity massage chair allows for the complete weight of your back to be virtually supported by the backrest,...
  • S-TRACK ROLLER SYSTEM: S-track system allows the roller heads to massage along the back from the neck down to the lower spine with a...
  • Computer Body Scan System

Last update on 2024-05-28 at 06:38 / Affiliate links / Images from Amazon Product Advertising API / More info

Product Details

Osaki is one of the leading distributors of electronic massage chairs, handheld massagers, foot massagers, fitness machines, and back relief products. They specialize in importing and distributing products straight to consumers.


• Recommended User Height (approx.): 5’4 – 6’4″
• Recommended Max. User Weight (lbs): 265
• Power Consumption (Watts): 250
• Weight (lbs): 214
• (H” x W” x D”): 47x32x46
• Colors: Black/Beige,Charcoal/Beige,Brown/Black,Cream/Tan

Note: The OS-4000’s synthetic leather can leave a stain over time when placed directly on your carpet. You’ll want to insert a rag or something disposable in between the chair corners and your flooring if you want to keep your landlord (or your spouse) happy.


Osaki provides a 1 year parts/ labor in-home warranty and a 3-year limited warranty.

Main Features

• Zero gravity design
• Designed with a set of S-track movable intelligent massage robots, with a special focus on the neck, shoulder and lumbar massage according to your body curve
• Automatically detects the whole body curve as well as makes micro adjustments which give a more humanistic and scientific massage
• Designed with six unique auto-programs: Healthcare, Relax, Therapy, Smart, Circulation, and Demo
• Automatic massage for the upper body (shoulder, neck, back and lumbar) and the low body (buttocks, thighs, calves and feet)
• Manual massage for the upper body with three options: full body, partial and fixed
• Six massage styles: rolling, kneading, clapping, shiatsu, Swedish and combo
• Five levels of speed & intensity
• Three kinds of width adjustable settings: wide, medium and narrow
• Air pressure massage for your back (two airbags), with five intensity options
• Air pressure for your lower body (twenty-six airbags), with five intensity options

See it in action in this informative video:


Osaki OS-4000 Zero Gravity Masssage Chair


Value for Money

The OS-4000 is one of the lowest-priced massage chairs on the market. It gives you a nice round of features difficult to find at that price point. Some of which are zero gravity, highly customizable massage settings, and preset programs.

This massage chair is great for the budget-conscious buyer, and there are colors to fit most homes.

Zero Gravity

This is always a plus. You want to be able to lie down in the ideal de-stressing position (feet level with or a few inches above the heart) for a more effective massage.

Enjoyable and Customizable Massage

The OS-4000 gives a relaxing massage that can be easily enjoyed by everyone in the family, young and old alike. It has several settings with varying levels of intensity, heat, and vibration.

From its preset programs, Relax and Circulation are the most popular while Smart is too intense for some people.


Tricky To Carry And Install Alone

The Osaki OS-4000 massage chair is over 200 lbs. Its awkward size makes it a struggle to maneuver through the house if you’re alone. Save yourself a hernia and call a friend (or professional movers) for help.

As mentioned, the chair is quite large and will be even larger after it’s set up, so make sure you have it in the room where you want it to stay before proceeding with the installation.

You only need to install 4 screws (to attach the chair arms), but it’s surprisingly difficult if you’re trying to do it by yourself. The manual is badly translated to English and therefore unhelpful. This isn’t a big issue as it it’s fairly easy to figure out what goes where.

The main problems are that: 1) the chair arms you’re trying to attach are heavy, and 2) the slots you’re trying to drive the screws into are quite small and easy to go off-track from. You’ll be wishing you were an octopus with a few more arms before you’re done.

Fortunately, the problem is easily solved by getting a household member or bribing a friend to be your chair arm holder (or screw attacher, whichever you’d like).

Installation takes 1-2 hours solo, or half an hour with two people.

One Size Doesn’t Fit All

Despite Osaki’s claim of the OS-4000 fitting people up to 6’4”, you may still find yourself in some difficulty if you’re over 6 feet. You may also have problems if you have broad shoulders (more than 19” or so).

If you’re a big guy that matches the description above, you’ll find that the neck massage doesn’t quite work for you (or at all) because your height doesn’t let you align for it. Additionally, fitting your shoulders into the OS-4000’s shoulder panels will be a challenge.

It’s possible to fix this with your handy screwdriver if you’ve got the knack and the time for tinkering.

Case in point: one handy gentleman reported that he removed the 3 mounting bolts on the sides of the shoulder panels and reattached them to the outer holes instead, using a couple of bolts to make them wider. Impressive DIY skills.

If, like me, you’re not that handy with a screwdriver, you can check out the Osaki OS-3D Cyber Pro which has an additional 1.5 inches in shoulder width.

High Learning Curve for the Controls

As mentioned earlier, the manual is badly translated to English and lacks pertinent information. It is deeply frustrating.

The OS-4000 has buttons like Imelda Marcos had shoes, and some of them may require a rocket scientist to figure out. As Spider-man’s uncle said – “With great customizability comes a great confusion – if you don’t have proper instructions.”

Some buttons are easy to figure out: you can use the preset programs, adjust the chair slope, the heat, and so on. Some of the buttons, however, don’t visibly do anything. Or maybe they only work in conjunction with each other… pressed in a certain pattern… at a certain speed… during the vernal equinox…

Weak Roller Intensity

The airbags can go up to a pretty high pressure level, but the massage rollers come up short in comparison.

If limp noodles giving you a back rub isn’t the massage sensation you’re after, you can fold back the headrest and back padding for a more vigorous experience.

This isn’t precisely a big con per se, as it’s easily fixed and, to be fair, the fix is actually noted in the manual (yes, we read the manual. The frustrating, badly translated manual. That’s how serious we are about finding the right massage chair for our home spa).

Questionable After Sales Support

Osaki doesn’t seem to like this brain child as much as its other products; or maybe they’re just really, really busy at the moment. Whatever the reason, quite a few unhappy customers these days seem to have difficulty getting support (or any response at all) for their defective OS-4000s when they call the 888 number. Caveat emptor.

There’s A Newer Model At The Same Price

Osaki came out with the OS-4000T in 2014, giving us a clone of their 2013 OS-4000 bestseller with two notable differences: new massage rollers in the ottoman (yay, foot massage) and improved synthetic leather (yay, prettier leather).

The kicker is that the OS-4000T is the exact same price as its older brother OS-4000, meaning there is no reason to get the older model when you can get the upgraded foot-massaging, shinier-faux-leather version at the same cost.


The Osaki OS-4000 was popular in 2013, but better models have come out since then, for close to or the same price. It’s still possible to enjoy this chair, but only if factors fall exactly right for you: if you fit into the chair, if you can figure the controls out, if you have the good fortune of not needing after-sales support.

Frankly, with these troublesome flies in the OS-4000’s oatmeal, you’re better off looking elsewhere for your ideal massage chair.

And if you really want this chair, anyway, get the Osaki OS-4000T instead for the same price, with added features.

Osaki OS-4000, 1 Count (Pack of 2), Taupe
31 Ratings
Osaki OS-4000, 1 Count (Pack of 2), Taupe
  • ZERO-GRAVITY MASSAGER: Zero-gravity massage chair allows for the complete weight of your back to be virtually supported by the backrest,...
  • S-TRACK ROLLER SYSTEM: S-track system allows the roller heads to massage along the back from the neck down to the lower spine with a...
  • Computer Body Scan System

Last update on 2024-05-28 at 06:38 / Affiliate links / Images from Amazon Product Advertising API / More info

Author: Mary Lou
In the Before Times, Maru spent vacations traveling and making stops at showrooms to test the latest massage chair models. Nowadays, she’s hunkered down in her small sunlit home dotted with her ever-growing collection of fiddle fig trees, indoor plants, and Himalayan salt lamps. Find her at LinkedIn.