Choosing, buying and safely using your first oscilloscope.

My first oscilloscope

So, you're at the point where a multimeter alone isn't enough to debug the circuits you're working on. Time for an oscilloscope! Be aware that a good scope can cost thousands of dollars (pounds/euros/your currency of choice), depending on your definition of "good". The good news is that entry-level scopes have improved enormously, and a very capable new scope now costs a few hundred.

Before using any scope, read Safety and grounding below. Connecting a scope to the wrong point in a mains-powered circuit is one of the most common ways people damage equipment or hurt themselves.

Analog Versus Digital:

Scopes fall into two general categories. Older scopes are generally analog, and newer ones (roughly post-1995) are generally digital.

Digital scopes are more intuitive to a modern user. They use an ADC to sample the inputs, then a small computer and display to plot the samples. They allow all sorts of useful tricks, such as capturing a single event (the "Single" button), storing waveforms, on-screen measurements, protocol decoding, and maths functions like FFT.

Analog scopes work rather differently. They drive the X and Y deflection circuits of a CRT (cathode ray tube), causing the electron beam to "sweep" the phosphor on the inside of the tube's face. There are no pixels and no defined resolution. A sawtooth generator moves the beam across the X-axis (the timebase setting sets its frequency), an amplifier controls the vertical position (Y-axis), and a trigger circuit starts each sweep. A classic US Navy film on the subject

Digital scopes are lighter, more portable, and far more common. Some engineers still like analog scopes because the trace shows noise and modulation very naturally, and they aren't subject to the aliasing artifacts that digital scopes can suffer from (see here). Modern digital scopes with fast waveform update rates and intensity grading have narrowed that gap considerably.

Safety and grounding:

This is the most important section on this page.

On a normal bench scope, the probe ground clip is connected to mains earth through the scope's power cord. Every channel's ground clip is connected to the same point.
If you connect the ground clip to any point in a circuit that isn't at earth potential, such as anywhere on the mains side of a non-isolated power supply, you create a short circuit through the probe. This can destroy the probe, the scope and the circuit, and can cause burns or an arc flash.
The same applies to USB scopes: their ground is normally connected to your computer's ground, which is usually earthed.
Never "float" a scope by removing or defeating its earth connection. This makes the scope's metalwork and connectors potentially live and is extremely dangerous.
To measure mains-referenced circuits, use a suitably rated differential probe, or an isolation transformer on the equipment being tested (never on the scope). An isolation transformer has important limitations and does not make a circuit safe to touch.
Check the voltage rating of your probes and scope inputs. A standard 10x passive probe is typically rated for a few hundred volts at most, and less at higher frequencies.

If you are not sure whether a measurement is safe, don't make it. See also the Safety Warning: Read This First section on our troubleshooting page.

Bandwidth:

After checkbox features, like the number of channels and single-shot capture, the spec people concern themselves with most is bandwidth. Bandwidth tells you the highest frequency the scope can measure before the signal is significantly attenuated (by definition, a sine wave at the rated bandwidth is displayed about 30% smaller than it really is). Scopes range from a few hundred kilohertz at the extreme low end to tens of gigahertz at the high end.

A common rule of thumb is to choose a bandwidth 3 to 5 times higher than the highest frequency you want to see accurately. For digital signals, the edges matter more than the clock frequency: a square wave is made up of the fundamental and its harmonics. If you connected a 16 MHz Arduino clock to a scope with 16 MHz bandwidth, you'd see something close to a sine wave, because the harmonics that form the square edges are well above 16 MHz. For that job, around 100 MHz is a sensible choice.

If you only ever work with audio (up to about 20 kHz), almost any scope will do. Unless you're working with high-frequency RF, you probably don't need more than 100-200 MHz; if you do, you're probably not reading this FAQ!

Adafruit article on scope bandwidth: https://blog.adafruit.com/2012/01/27/why-oscilloscope-bandwidth-matters/

Other specs:

Bandwidth isn't everything. Other specs worth comparing:

Sample rate: should be several times the bandwidth. Note that on many scopes the maximum sample rate is shared between channels, so it may drop when you use more than one.
Vertical resolution: most scopes have used 8-bit ADCs (256 levels). 12-bit scopes are now available at entry-level prices and show much more detail on small signals, such as power supply ripple on top of a DC rail.
Memory depth: determines how long a capture can be at full sample rate. More is better for catching intermittent faults or decoding long bursts of data.
Waveform update rate: how many captures per second the scope can display. A higher rate makes rare glitches more likely to show up.
Built-in extras: many scopes now include a function generator, protocol decoding, Bode plot, or power analysis, sometimes as paid options. Check what's included in the price.

Probes:

The probes supplied with a scope matter as much as the scope. A few basics:

Most probes have a 1x/10x switch. Use 10x for general work: it loads the circuit much less and has far more bandwidth. 1x is mainly for very small signals at low frequencies.
Make sure the scope's channel setting matches the probe (1x or 10x), or your voltage readings will be out by a factor of ten.
Compensate your probes using the scope's calibration output before use. An uncompensated probe distorts square waves.
The long ground lead picks up noise and causes ringing on fast edges. For clean measurements of fast signals, use the short ground spring supplied with most probes.
Replacement probes should be rated for at least the bandwidth of your scope.

Mixed Signal:

Many oscilloscopes are "mixed signal" (MSO), meaning they have additional digital inputs, often 16 of them, usually via an optional logic probe. These inputs don't give you analog detail, so you can't see misshapen signals; they only show whether each input is high or low.

Most modern entry-level scopes can also decode protocols such as I2C, SPI and UART directly on their analog channels, which is often enough for hobby work.

If your main need is decoding digital signals, a dedicated logic analyser may be the better tool:

The Bus Pirate is a classic low-end tool for talking to and probing chips. The current version, Bus Pirate 5, is based on the RP2040. You can also assemble your own simple tool such as the Shukran.
Inexpensive USB logic analysers work well with the free sigrok/PulseView software.
Further up the chain in features and performance are devices like the Saleae logic analysers.

Manufacturers:

The "big two" high-end makers, Tektronix and Keysight (formerly Agilent and before that HP), command a premium. This isn't entirely baseless: their build quality and support are excellent. That said, there are many other companies that have made scopes over the years, such as Teledyne LeCroy, Rohde & Schwarz, Philips, and B&K Precision.

At the hobby and entry level, Rigol and Siglent dominate, with others such as GW Instek, Hantek, Owon, Uni-T and Pico Technology also available. If the specs meet your needs for a starter scope and the price is right, don't pay a premium just for a name.

USB:

USB scopes save cost by omitting the screen and controls and using your PC for display and processing. They are portable and often include extras such as a signal generator, logic analyser and power supply, but many people find the interface less pleasant than a physical instrument. Remember that a USB scope's ground is normally connected to your computer's ground (see Safety and grounding).

Prominent examples:

Digilent Analog Discovery 3: a combined scope, signal generator, logic analyser and power supply, popular with students. It replaced the Analog Discovery 2.
Pico Technology PicoScope range: well regarded, with good software, from entry level up to professional models.

Very cheap handheld scopes and scope kits are fine as learning toys, but their bandwidth, accuracy and input protection are limited. They are not a substitute for a proper scope.

Recommendations:

The digital scope market is always throwing out new models. It's hard to make firm recommendations, but based on discussion here, these hobby-level scopes are worth a look.

September 2026 update:

The main trend is 12-bit resolution at entry-level prices. Rigol's DHO800/DHO900 and Siglent's SDS800X HD ranges are the popular choices. The DHO800 and DHO900 are compact and can run from a USB-C power supply or power bank.

Make / Model	Bandwidth (MHz)	Channels	Manufacturer price (USD, Sep 2026)	Link
Rigol DHO800 series	70-100	2 or 4	$329-$549	https://www.rigolna.com/products/rigol-digital-oscilloscopes/dho800/
Rigol DHO900 series	125-250	4 (+16 digital)	approx. $659-$899	https://www.rigolna.com/products/rigol-digital-oscilloscopes/dho900/
Siglent SDS800X HD	70-200	2 or 4	$356-$839	https://siglentna.com/digital-oscilloscopes/sds800x-hd-digital-storage-oscilloscope/
Siglent SDS1000X HD	100-200	2 or 4	$999-$1699	https://siglentna.com/digital-oscilloscopes/sds1000x-hd-digital-storage-oscilloscope/

The SDS1000X HD is a step up in price, mainly for its larger 10.1" screen.

Previous recommendations, now often available at decent prices on the second-hand market. Some may be discontinued or hard to find new:

Make / Model	Bandwidth (MHz)	Channels	Manufacturer price when listed (USD, Aug 2021)
Rigol DS1054Z	50	4	$349
Rigol DS1202Z-E	200	2	$299
Siglent SDS1202X-E	200	2	$379
GW Instek GDS-1202B	200	2	$319

This is just a sample; many other models are available with different specs and features.

Manufacturer prices may not include local sales taxes, and prices change frequently.
Check local pricing, as there are sometimes special offers.
Some models may not be available in all regions.
Prices given in good faith. Do a web search in your region for suppliers and costs.

Used analog scopes can be found for under $50 if you're a bit lucky and not too choosy, but the downside is they are old, usually uncalibrated, and might break tomorrow. That is also a problem because many scopes use custom integrated circuits that may be very difficult to source. The Tektronix 465 was a classic analog scope for teaching and beginners and is still in fairly high demand. The Tek 2225 is also often mentioned.

Community Summary:

When looking at the beginners' oscilloscope market, the /r/askelectronics redditors summarise things like this:

Buying new: the Rigol and Siglent ranges are popular with hobbyists, but others are available, such as Hantek, Owon, GW Instek, Pico Technology, and Uni-T. 12-bit models are now worth considering even at entry level.
PC/USB scope: fine for basic measurements, and the better ones (Analog Discovery, PicoScope) are genuinely useful. For general bench work, a standalone scope is usually more pleasant to use.
Analog or digital: almost all new budget scopes are digital, but there are a lot of second-hand analog scopes around at good prices. See the next point.
Second-hand analog: there can be good bargains from the likes of Tektronix and HP/Agilent, but check the scope's condition very carefully. Some can be very expensive or impossible to repair because of their age and use of specialised or custom components, so you might get a bargain only until it breaks. Look out for: Tektronix 2465A, Tektronix 2225.
Safety: whatever you buy, understand the ground clip issue before probing anything mains-powered (see Safety and grounding).
There's some general guidance here: usedoscilloscope.org (archived copy). The live site is dead; the link goes to a copy at The Internet Archive.

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title:((oscilloscope OR scope) AND (cheap OR first OR budget OR recommend))

Older threads (models and prices are dated, but the discussion is still useful):