Inverter Vs Transformer Welder: Differences Explained In Details

The strength and the quality of the weld depend on the power supply the welding machine is using. So, even if you are using the traditional transformer welder, read this article to learn what more the latest inverter welding machine has to offer.

Most welders are confused on what is the difference between inverter vs transformer welder. In this article, I have tried to do a head-to-head comparison between them and bring out their upsides and downsides.

So, are inverter welders better than transformer welders?

The answer is yes, they are specially designed to save space and energy. Being small and lightweight it’s easy to carry them around. Stable arc along with continuous combustion uses energy more efficiently and guarantees better weld quality.

How does it implement better productivity than its counterpart? Read the full article to learn that.

What Is A Transformer Welder?

It takes the alternating current (AC) from the utility mains which is usually 230 or 115 VAC and converts them into a low voltage, high amperage current in the secondary winding. In the more expensive machines, there is a rectifier to change the AC output into DC.

By permitting the user to select the output voltage from a set of taps on the transformer’s secondary winding, the welding current and the secondary voltage can be adjusted.

As this machine uses AC power, which changes the direction of current and voltage frequently, so here the arc stability is poor. The arc is extinguished and re-ignited 100 to 120 times per second. The combustion is not continuous, so it takes more time to get heated. Furthermore, you won’t be able to control the welding process precisely. This is why it supports stick and some other arc welding techniques only.

What Is An Inverter Welder?

Inverter welding machines use semiconductor devices to accurately maintain the shape of the current. At first, it rectifies the AC power from the mains to DC power. Then this DC power goes into a step-down transformer to produce the desired current or voltage as output. The machines are capable of maintaining a steady current flow.

This prevents voltage and temperature fluctuations and allows a steady arc. As a result, the weld’s quality and appearance are greatly improved. On top of that, it allows the user to work with multiple types of base metal.

It puts the welders in control. One will be able to adjust the shape of the current at the microsecond level. Furthermore, one will be able to do multi-process welding like SMAW, GMAW, or GTAW and Stick, TIG, MIG, FCAW, arc gouging, and even pulsing. It consumes less energy and filters metal while staying cool even after using it for a long time.

Inverter Vs Transformer Welder: Which One Is Better

Before diving into a detailed explanation, have a look at this brief comparison chart.

Factors Considered Inverter Transformer
Size Compact Larger
Weight Less More
Portability More Less
Energy Efficiency More Less
Power Output Range More Limited
Applications MIG, TIG, Stick, FCAW, arc gouging, pulsing, etc. Mainly used for industrial-grade stick welding or other arc welding techniques
Beginner-friendliness Yes No, requires prior experience.
Heat-generation Low because of the in-built cooling fan keeps it cool even after prolonged usage. Higher as it gets overheats quickly.
Life Expectancy Low High
Price Higher Lower

Why is an inverter welder better?

Looking at the chart, you have probably got an idea why inverters are far more efficient than transformers. Read on to learn its functionality, applications, pros, and cons.

Energy Efficiency

Inverters are comparatively smaller in size because of using semiconductor devices and smaller transformers. Therefore, they can be installed in narrower spaces. Another advantage of its compact size is shorter or direct connections between the electrical components. This is why the resistance is less here and efficiency is superior.

Again, it has smaller cooling fans that require less energy to move. As a result, it prevents energy loss. That being said, every electrical component of an inverter is designed to reduce energy and use it efficiently.

On the other hand, being larger in size transformer has more wiring, which means greater resistance and more energy loss in the way. When it is plugged into the utility mains, it consumes power even if it is not connected to any device.

Output Level

In the traditional transformer welder, there are some fixed steps of power output level. A set of taps on the transformer’s secondary winding allows the welder to select the output voltage. As a result, you will not be able to set any power output level in between those steps.

Whereas, inverters are designed to be step-less. You can adjust them as you want, simply by touching the screen or rotating the knob. Compared to its transformer counterpart which can provide only 60% power output, it can deliver 93% more productivity.


Inverter welders can be used for prolonged hours without getting overheated. So, you can use them for a long time without any issue. The cooling fans inside it keep the air cool by getting rid of the operating heat. This allows for better productivity.

On the contrary, the transformer runs by AC power. Continuous combustion can’t happen because the arc ignites 100-120 times per second. This is why the heating time is more. Again, it gets overheated quickly. So, if you are a heavy welder, you know which one to skip, right?

Weight and Portability

The inverters are light-weight and compact in sizes, which means it’s easier to move them around. Whereas, transformers are larger in size and heavier in weight. Maneuvering them around the job site is more difficult.

Moreover, if you are tight in space, keeping it in a narrow space might be tough for you.  If your work requires a portable power source, this is not what you should go for because It requires power from utility mains.

Applications and Preferable Environment

One of the inverter welding machine advantages is, it offers a wide range of welding processes for you to choose from. Stick, TIG, MIG, FCAW, arc gouging and even pulsing can be done by this machine. For its convenient size, you can use it in a controlled indoor environment or your home workshop. For the professional welders, using it in a constructional or Petro-chemical site will be okay too.

The traditional transformers are mostly used in professional-grade stick welding and other arc welding techniques. They can be used for welding at any place be it indoor or outdoor environment. Even in dusty or windy weather conditions, there won’t be any problem working with them. You can see them at construction or industrial sites too.

Required Experience

Inverters are more beginner-friendly when it comes to welding. It allows the user to set every parameter individually. So, it helps you to get the settings right. As you get more skilled using it you can go for more customized settings too.

On the other hand, transformer welders have fewer controls to adjust and operate. You mainly set those based on instinct. Therefore, it requires some prior experience.


Though both of their prices depend on their size and functionality, usually it is cheaper to purchase or hire a transformer welder than its inverter counterparts. However, going for an inverter saves you money in the long run by saving money in electricity costs. In this way, it can surely make up for the higher price in no time.

Life Expectancy

One of the downsides inverters have is their life expectancy is way less than their traditional counterparts.

How long do inverter welders last?

Regardless of use, it has 12 years of shelf-life expectancy. As inverters are computer-operated, there is a lot of sensors that can go wrong and cause a mess. Whereas the old transformer welders definitely have a way longer track record than this.

Which One Is More Suitable for You Between Inverter Welder and Transformer Welder?

Now, if you are quite experienced in welding and just need to do stick or arc welding then you can go for the transformer welder. Transformer welding machine advantages are its low-cost and longer service life. For the old-school welders who want a simple machine with basic welding capability, it’s enough.

But from energy efficiency, power gain, and maneuverability inverters are way more superior. They can work on a wide range of base metals and guarantees a better outcome. You can carry out any welding process with just one machine.

Again, you can adjust the control parameters as you like. So, this is the must-have for beginners and tech-geeks. Besides, if your work requires sophisticated welding this is what you should go for. Though it may seem pricier than its counterpart, it will surely make up for that cost by saving energy and providing better service.

The Bottom Line

So, between the inverter vs transformer welder, the inverter has more advanced technology to get rid of the disadvantages of its traditional counterpart. It has better control and arc stability which is why it can give you a more seamless weld. Again, with just one machine you can carry out multiple welding techniques.

However, the downsides of this machine include a higher price point and the need for a replacement if any electrical component gets damaged. Keeping these disadvantages in mind, choose the one that better matches the task you need to carry out more often.