Best Socket Tester Under £100
Find the best socket tester under £100 for checking wiring faults, RCD trips, and voltage presence. We compare the top models from trusted brands to help you choose the right tool for DIY and professional use.
Quick answer
The best socket tester under £100 is the Kewtech KEWTST200 for its clear fault indication and rugged build. For a budget pick, the Sealey ST01 offers reliable basic testing at a lower price.
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Research updated June 2026.
Kewtech KEWTST200
Clear fault indication and robust build for professional use.
| Product | Best For | Key Spec | Rating | Price |
|---|---|---|---|---|
| Kewtech KEWTST200 | Overall Best | 7 fault LEDs, RCD test | 4.8/5 | Check price |
| Sealey ST01 | Budget Pick | 3 fault LEDs, no RCD | 4.5/5 | Check price |
| Bosch GCT 30 | Professional Use | 30mA RCD test, voltage | 4.7/5 | Check price |
| Draper 65150 | Versatility | LED & audible alarm | 4.6/5 | Check price |
| Stanley ST-01 | DIY Starter | Basic fault check | 4.3/5 | Check price |
What Is a Socket Tester and Why Do You Need One?
A socket tester is a handheld device that plugs into a standard electrical outlet to check for wiring faults. It uses LED indicators to show if the socket is wired correctly or if there are issues like reversed polarity, missing earth, or a live-neutral swap. This tool is essential for anyone working with electrical installations, from DIY enthusiasts to professional electricians.
Using a socket tester helps prevent electrical shocks and equipment damage. It provides a quick and safe way to verify that a socket is properly wired before plugging in expensive appliances. For under £100, you can get a reliable model that covers the most common faults.
Best Socket Tester Under £100: Top 5 Picks
Kewtech KEWTST200
Best OverallPros
- Clear LED fault indication
- Built-in RCD test
- Rugged construction
Cons
- Higher price point
- No voltage display
The Kewtech KEWTST200 is a professional-grade socket tester that offers comprehensive fault detection. It uses seven LED indicators to identify common wiring errors, including reversed polarity, missing earth, and live-neutral swaps. The built-in RCD test function allows you to check residual current devices without additional equipment.
Owner reviews highlight its reliable performance and durable build, making it suitable for regular use on site. The clear labeling on the faceplate simplifies fault interpretation, even for less experienced users. While it costs more than basic models, it remains under £100 and delivers excellent value for those needing thorough testing.
Sealey ST01
Best BudgetPros
- Very affordable
- Simple to use
- Compact design
Cons
- Limited fault detection
- No RCD test
The Sealey ST01 is a basic socket tester designed for quick checks on standard UK sockets. It uses three LEDs to indicate correct wiring, reversed polarity, or missing earth. This model is ideal for homeowners who want a simple tool to verify their sockets are safe before use.
Owner reviews note its ease of use and low cost as major advantages. It does not include RCD testing or voltage display, so it is best for basic fault detection. For the price, it offers reliable performance for occasional DIY tasks.
Bosch GCT 30
Best for Professional UsePros
- Professional build quality
- 30mA RCD test
- Voltage detection
Cons
- Slightly bulkier
- Higher price
The Bosch GCT 30 is a robust socket tester designed for professional electricians. It features seven fault indicators and a built-in 30mA RCD test function, allowing you to check residual current devices quickly. The unit also includes a voltage detection feature for added safety.
Owner reviews praise its durability and accurate readings, making it a reliable tool for daily use on construction sites. The larger size may be less convenient for tight spaces, but the performance justifies the footprint. It is a top choice for those who need professional-grade testing under £100.
Draper 65150
Best VersatilityPros
- Audible alarm for faults
- Clear LED display
- Good build quality
Cons
- No RCD test
- Alarm can be loud
The Draper 65150 socket tester combines LED indicators with an audible alarm to alert you to wiring faults. This feature is helpful when working in noisy environments or when you cannot see the LEDs clearly. It covers five common fault conditions, making it more comprehensive than basic models.
Owner reviews appreciate the added audio feedback, which reduces the chance of missing a fault. The unit is well-built and fits standard UK sockets securely. While it lacks an RCD test, it offers good versatility for general socket checking at a reasonable price.
Stanley ST-01
Best DIY StarterPros
- Low cost
- Easy to understand
- Brand reliability
Cons
- Basic fault coverage
- No RCD test
The Stanley ST-01 is a straightforward socket tester aimed at DIY users. It checks for three common faults: correct wiring, reversed polarity, and missing earth. The simple LED display makes it easy to interpret results without any training.
Owner reviews highlight its affordability and ease of use as key benefits. It is a good starting point for homeowners who want to verify their sockets are safe. However, it lacks advanced features like RCD testing, so it is best for basic checks only.
What to Check Before Buying a Socket Tester
Consider the types of faults you need to detect. Basic models cover three faults, while advanced units can identify seven or more. If you work with RCDs, choose a tester with a built-in RCD test function. Also check the voltage rating to ensure it matches your local supply, typically 230V AC in the UK.
Build quality matters for durability. Look for models with robust casings and clear labeling. Some testers include audible alarms or voltage detection, which can be useful in certain situations. Finally, consider the brand reputation and warranty period for peace of mind.
Mistakes to Avoid When Using a Socket Tester
Do not rely solely on a socket tester for full electrical safety. It does not check for overloaded circuits or insulation resistance. Always use a socket tester as a preliminary check and consult a qualified electrician for comprehensive testing.
Avoid using a damaged tester or one that shows inconsistent results. Replace batteries if the LEDs are dim, as low power can cause false readings. Never insert a tester into a socket that appears damaged or has exposed wiring.
FAQs
What is a socket tester used for?
A socket tester checks if a standard electrical outlet is wired correctly by detecting common faults like reversed polarity or missing earth.
Can a socket tester detect all wiring faults?
No, it only detects specific faults related to socket wiring, not issues like overloaded circuits or insulation breakdown.
Do I need an RCD test on my socket tester?
It is helpful if you work with residual current devices, but not essential for basic socket checks.
Is a socket tester safe to use?
Yes, when used correctly on standard sockets, it is safe. Always inspect the tester for damage before use.
What does a green light on a socket tester mean?
A green light typically indicates correct wiring, but always refer to the specific model's guide for exact meanings.
Can I use a UK socket tester in other countries?
Only if the voltage and plug type match. Most UK testers are designed for 230V AC and BS 1363 sockets.
How often should I test my sockets?
Test sockets when you move into a new home, after electrical work, or if you notice any issues with appliances.
What is the difference between a socket tester and a multimeter?
A socket tester is a dedicated tool for quick fault checks, while a multimeter measures voltage, current, and resistance in more detail.
Do socket testers work on USB sockets?
No, they are designed for standard AC power sockets, not USB outlets.
Can a socket tester check for earth faults?
Yes, most models include an indicator for missing or faulty earth connections.
Are cheap socket testers reliable?
Basic models from reputable brands like Sealey or Stanley are reliable for simple checks, but may lack advanced features.
What does a socket tester do if there is a fault?
It lights up specific LEDs or sounds an alarm to indicate the type of fault, such as reversed polarity or missing neutral.
Our verdict
The Kewtech KEWTST200 is the best socket tester under £100 for its comprehensive fault detection and RCD test. For a budget option, the Sealey ST01 provides reliable basic checks at a lower cost. Choose based on your need for advanced features versus simplicity.