A function generator is unavoidable if you are an electrical circuit designer, technician, or product quality auditor. As the name suggests, function generators produce electrical waveforms for testing other equipment and systems. They are one of the most commonly used in test and development systems.
Function generators come in all forms, and different types also exist. They either generate arbitrary waveforms, audio signals, functions, pulses, or radio frequency signals. What you buy depends on the intended use or the field you are in.
In terms of form factor, the function generators also come in various models. Some are designed as lab equipment to sit on benchtops, while others are more portable. You can even hold them in your hand and carry them around with you. So, which is the best function generator to buy?
Your buying decision depends on many factors, such as the intended purpose, cost, and others. Fortunately, we have spent many hours researching and compiling the following best function generators. Read on for more detail and our recommendations!
Top 6 Best Function Generators in 2025
The different function generator brands and models in the market make it challenging to choose the most appropriate one to buy. However, we already have a list of the best function generators you can consider. Let’s dive deeper into what each option offers to help you make the right decision.
| Products | Overview | Sampling Rate | Bandwidth | Vertical resolution | Price |
|---|---|---|---|---|---|
| 1. Siglent Technologies SDG2042X Arbitrary Waveform Function Generator |  | 1.2 GSa/s | 40MHz | 16 bits | |
| 2. GW Instek AFG-2105 Arbitrary DDS Function Generator | 20 MSa/s | 5MHz | 10 bits | ||
| 3. Goupchn Programmable DDS Signal Generator |  | 300 MSa/s | 60MHz | 14 bits | |
| 4. Koolertron Upgraded 15MHz DDS Function Generator |  | 266 MSa/s | 15MHz | 14 bits | |
| 5. KNACRO 15MHz DDS Signal Generator |  | 200 MSa/s | 15MHz | 14 bits | |
| 6. Hantek 2D72 Handheld Waveform Generator |  | 250 MSa/s | 70MHz | 12 bits |
1. Siglent Technologies SDG2042X Arbitrary Waveform Function Generator [Best Overall]
At the top of our list of the best function generator is Siglent Technologies SDG2042X. This equipment is a dual channel 40 MHz sine wave generator with a large LCD touchscreen display. It has a vertical resolution of 16-bit and an in-built high precision frequency counter.
The Siglent Technologies SDG2042X function generator also uses arbitrary waveform editing software. This application supports multiple ways of generating arbitrary waveforms, including manual drawing, line drawing, equation drawing, coordinate drawing, and many others. That ability makes it easy to use.
Siglent Technologies SDG2042X uses innovative square/pulse waveform generation technology that overcomes the shortcomings of DDS. The EasyPulse Technology assists in the production of low jitter square or pulse waveforms. It also uses TrueArb technology to generate arbitrary waveforms point by point while keeping all the benefits of the traditional DDS.
This function generator is best suited for various applications, such as electrical circuit function tests, education and training, environment signal simulation, IC test, etc.
Pros:
- Dual channel with touchscreen LCD display
- High vertical resolution of 16 bit
- Easily interfaces with other equipment through LAN and USB
- Built-in high precision frequency counter
- High-performance sampling system
- 196 built-in arbitrary waveforms
Cons:
- Very expensive
- Not portable
2. GW Instek AFG-2105 Arbitrary DDS Function Generator
GW Instek AFG-2125 Arbitrary function generator is the second on our list because it offers professional features and functions. This equipment boasts a high vertical resolution of 10 bits, 20MSa/s sampling rate, and 4K [point memory for the arbitrary waveform.
GW Instek AFG-2125 generates sine, square, triangular, noise, and arbitrary waveforms at a frequency ranging from 0.1Hz to 25MHz. It is also capable of a 1-99% adjustable duty cycle for square waveforms. You can easily adjust the waveform properties by pressing buttons and turning a knob on the interface. It gives you control over waveform amplitude, DC offset, and other parameters, and all are shown on its 3.5-inch LCD screen.
This equipment has a built-in frequency counter, AM/FM, FSK modulation system, and sweep functions. It is a complete tool to have in your laboratory for various applications.
Pros:
- Adjustable Duty Cycle
- Comes with arbitrary waveform editing PC software
- USB interfacing with storage devices
- High sampling rate
- Waveform parameters are adjustable
Cons:
- Relatively expensive
- Not portable
3. Goupchn Programmable DDS Signal Generator
Goupchn Programmable DDS is the third best function generator but should have ranked higher. This professional equipment is feature-rich and has many functions. You can use it to generate different waveforms, including sine wave, square wave, triangular wave, and arbitrary wave.
This instrument has a maximum frequency range or bandwidth of 60MHz. It has different functions such as waveform modulation, frequency sweep, measured signal frequency, VCO, and programmability.
You can adjust the amplitude, phase, duty cycle, and output signal frequency. That information is also displayed on its LCD screen for quick reference.
Frequency characteristics:
- Sine wave frequency range: 1nHz-60MHz
- Square wave frequency range: 1nHz-30MHz
- Triangle wave frequency range: 1nHz-50MHz
- Pulse wave frequency range: 1nHz-30MHz
- TTL digital wave frequency range: 1nHz-20MHz
- Arbitrary wave frequency range: 1nHz-50MHz
- Pulse width adjustment range: 5nS~4S
- Pulse period adjustment range: 10nS~40S
- Frequency minimum resolution: 1nHz
- Frequency accuracy: ±5ppm 0 to 50℃
The Goupchn Programmable DDS’s other features include voltage control, interface customization, burst function, modulation function, etc.
Pros:
- Precise and adjustable pulse width
- Interface customization with up to 4 colors
- Modulation, burst, and other functions
- Programmable signal output for automation
- Multiple connection mode
- Equivalent performance dual channel output
Cons:
- Poor customer support services
- Relatively low build quality
4. Koolertron GH-CJDS66 Upgraded 15MHz DDS Function Generator
Koolertron Upgraded 15MHz DDS Function Generator is a 15MHz high precision dual channel equipment for signal generation. It has a large-scale FPGA integrated circuit and high-speed MCU for stable operation. Its internal circuitry also includes a benchmark active crystal oscillator that further strengthens the stability of the signal.
This dual channel generates a precise, stable, low distortion output signal for testing circuits and other applications. You can use it to get an accurate and noise-free square wave, triangular wave, sawtooth wave, pulse wave, user-defined waveforms, and many others. Additionally, you can set the two channels independently to produce different output signals according to your needs.
Koolertron function generator also has a linear sweep and logarithmic frequency sweep functions. It allows you to take frequency, period, and pulse width measurements. You can also define your waveform, store it, and recall them for later use using this equipment.
Koolertron function generator is a versatile instrument for electronic engineering, production lines, laboratories, and scientific research.
Pros:
- High-frequency precision
- Full range frequency resolution
- Dual channel with independent duty cycle adjustment ability
- Has other functions such as frequency meter and counter
- Relatively affordable
- Customizable output signals
Cons:
- Lacks sync output for triggering a scope in sweep mode
- No clear operation manual
5. KNACRO 15MHz DDS Function & Signal Generator
KNACRO is another cost-effective piece of equipment you can opt for if you have a low budget. It is a 15MHz dual-channel arbitrary waveform generator with a high sampling rate of 200MSs/s. Like the previous product, the KNACRO also has large-scale FPGA integrated circuits and a high-speed microprocessor for signal stability.
KNACRO function generator boasts useability, excellent technical parameters, multiple signal generation functions, waveform scanning, parameter measurements, etc. Despite the affordability, this instrument has many applications in different areas. Electronic engineering, teaching and researching, and laboratories are just a few places this instrument can make a difference.
Specifications and frequency characteristics:
- CMOS output range: 0-10V
- DC offset range: -9.99V to +9.99V
- Offset resolution: 0.01V
- Vertical resolution: 14 bits
- Sampling rate: 266MSa/s
- Frequency range: 1Hz-100MHz
- Output signal amplitude range: 0Vpp-20Vpp
Pros:
- Affordable
- Multi-functional device
- Excellent technical parameters
- LCD screen for simultaneous display of signal parameters from both channels
- Convenient and easy to use
Cons:
- Relatively low build quality
6. Hantek 2D72 Handheld Waveform Generator
Hantek 2D72 waveform generator appears on this list for its portability. Choose this product if you work in the field and need something you can easily carry around. This handheld instrument is a 70MHz 3-in-1 piece of equipment. It acts as an oscilloscope, waveform generator, and digital multimeter.
Hantek 2D72 waveform generator is designed for mobile engineers, technicians, and field researchers. You can easily fit it in your backpack. Besides, it has a 45-degree suspension bracket to make it stand on a bench. So, you can set up a workstation anywhere.
The instrument has a low-power design and has a large-capacity replaceable lithium-ion battery that can last for a whole day on a full charge. Recharging is also quick, taking only two hours.
You can use Hantek 2D72 to regenerate sine, square, triangular, trapezoidal, and other waveforms. It can produce sine waves at a frequency of up to 25MHz.
Specifications:
- Sampling rate: 250MSa/s
- Vertical resolution: 12 bits
- Sine: 1Hz-25MHz
- Square: 1Hz-10MHz
- Triangular: 1Hz-1MHz
- Trapezoid: 1Hz-5MHz
- Frequency resolution: 1Hz
Pros:
- Multi-functional instrument (oscilloscope, signal generator, and multimeter).
- Auto-power shutoff when idle
- Compact, lightweight, and portable
- LCD screen with adjustable backlight brightness and duration
- High sensitivity and accuracy
Cons:
- Relatively poor customer support
- Some bugs reported
Things to Consider When Buying A Function Generator
What specifications should you look for when buying a function generator? You will not just pick any equipment you find in the market, but the decision-making is also challenging. Consider the following factors:
1. Waveform type
A function generator can produce a square, sine, triangular, ramp, pulses, trapezoidal, sawtooth, and many other waveforms. It is ideal to buy an instrument that can give all these, or at least the ones you commonly use. Also, it is the choice when you want a signal generator with minimal sine wave distortion, the best triangular waveform linearity, and a symmetric output signal.
2. Resolution
The resolution of a function generator is the equivalent waveform and values you see on its screen. The higher it is, the better the presentation and output signal. Check its digital to analog converter (DAC) capabilities. The DACs are rated in the number of bits of data they can process. A 16-bit DAC is much better than a 3-bit DAC.
Buy a function generator with offsets and adjustable peak-to-peak output signal amplitude.
3. Bandwidth and Sampling Rate
The bandwidth of a function generator is its output signal attenuation frequency. This is usually 3dB relative to the DC amplitude. The higher the bandwidth of a function generator, the better it is.
The sampling rate of this instrument tells you how fast data is pushed from the memory to the DAC for conversion. This parameter is specified in Samples per second (Sa/s). A higher sampling frequency results in a more detailed output waveform.
4. Output Signal Amplitude
The output signal levels vary from one piece of equipment to the next. Most function generators on this list or in the market have about 10-12 peak-to-peak voltage. Anything below this range may be limiting the application of the signal generator. Go for a higher value if possible!
5. Output Impedance
This factor determines the amount of load a function generator can drive. It is the resistance of AC flow out of the instrument which saves the produced waveform. Typically, a reliable function generator has an output impedance of 50 ohms. Check this value before making any purchase.
6. Other Factors
Some function generators are multi-functional and have extra features you may not find in others. When buying a new one, check the frequency stability, phase lock capability, and modulation functions.
Conclusion
The function generator type you buy depends on your budget and the intended use. We have provided a buying guide to help you make an informed decision and get the best instrument. But we also have a few recommendations for you.
Siglent Technologies SDG2042X is our best choice if you can afford it. This function generator supports multiple ways of generating arbitrary waveforms, including manual drawing, line drawing, equation drawing, and coordinate drawing. It is also accurate, precise, and can produce many types of waveforms.
The second option is GW Instek AFG-2125 Arbitrary function generator. It features a built-in frequency counter, AM/FM/ FSK modulation system, and sweep functions and allows you to adjust the duty cycles of the output signal.
Lastly, you can consider Goupchn Programmable DDS. This equipment generates different types of waveforms and has multiple functions. It is also programmable, allowing you to use automation in the testing process.
Is one of the function generators above your choice? Does it cover as signal generator as well? These two instruments are a bit different. Make sure you know what you are buying.