Changes to UK motoring laws are on the horizon, with the Government expected to lower the drink-drive limit in England and Wales this autumn. If the plans go ahead, the legal limit will drop from 35 micrograms of alcohol per 100ml of breath to 22 micrograms – the same as currently in place in Scotland. So, the need for in-car breathalysers is becoming more apparent.
The move aims to improve road safety and reduce accidents linked to alcohol. For drivers, the message remains simple: if you’ve been drinking, don’t drive. Even small amounts of alcohol can affect reaction times, awareness, and decision-making behind the wheel.
That said, there are times when the danger isn’t from drinking before a journey, but from alcohol still in your system the morning after. A night out can easily lead to losing track of how many drinks you’ve had, and your body may still be processing alcohol hours later. Maybe you lost count of how many glasses you had, or just assumed you’d ‘sleep it off’. This is where a personal breathalyser can be a genuinely helpful tool.
The best breathalysers at a glance:
A quality breathalyser, used correctly, can give you an idea of whether you’re likely to be over the legal limit, helping you avoid unintentionally breaking the law and, more importantly, ensuring you’re safe to drive. However, it’s crucial to see breathalysers as a preventative measure, not as a way to push your drinking to the legal limit. Think of it as a safety check, not a challenge to see how much you can drink and still be legal.
While the safest choice will always be not to drive after drinking, these devices can provide an extra layer of reassurance for those occasions when you want to be sure the alcohol has entirely left your system before getting behind the wheel.
The best breathalysers 2025
Editor's pick
We've tested this model, and the accuracy is excellent. It is also country configurable and even gives you a timer until you're sober.
Pros
- Uses a fuel-cell sensor similar to those in police equipment, delivering accurate readings
- Features like “time-to-sober” estimates, and the option to automatically adjust to drink-drive limits in various countries add real-world practicality
Cons
- To remain accurate it requires to be recalibrated annually which will incur additional costs
Best compact breathalyser
Pros
- It uses an intermediate-level sensor and delivers accuracy rated at around ±0.20 ‰ BAC, which is impressive for this price point
- The Lite 2 is sleek and pocket-sized, making it portable and user-friendly
Cons
- Designed for occasional, casual use — not for heavy-duty or professional situations
The best value breathalyser
While the terminology can become hazy with police spec breathalysers, it does use the same (albeit smaller) sensor as the Pro Fuel Cell, and these are generally the best in the business. It represents slightly better value than the Pro Fuel Cell, too.
Pros
- Equipped with a fuel-cell sensor, the Excel delivers high precision, making it suitable for professional and frequent use
- The device has a short recovery time between tests, allowing for efficient multiple readings
Cons
- Regular calibration is necessary to maintain accuracy
Best compact digital breathalyser
Two AAA batteries provide power, but the unit also comes with a USB connector, which can be used to connect to a power source if the batteries go flat. The device can be set up to provide readings in different units and has 10 interchangeable mouthpieces that can be cleaned and reused.
Pros
- Features a USB charging port, offering an alternative power source when the batteries are flat
- The backlit LCD screen ensures readability even in low-light conditions, displaying BAC levels clearly for easy interpretation
Cons
- The semiconductor sensor provides decent accuracy, but it may not match the precision of fuel-cell sensors found in higher-end models
Best simple breathalysers for UK use
Pros
- The breathalyser is no larger than a cigarette, making it highly portable.
- Designed for single-use, the breathalyser is straightforward to use and results are displayed within minutes.
Cons
- While suitable for personal use, this breathalyser is not designed for professional calibration or use in legal settings
Best disposable breathalysers
Pros
- This disposable breathalyser meets the French NF certification standards — a requirement for motorists in France ensuring legal compliance
- It's compact and simple to use, perfect for holiday use or keeping in the car glove compartment
Cons
- Less accurate than digital fuel cell breathalysers
How to choose a breathalyser
When it comes to breathalysers, cheap ones will simply be rubbish. We did an investigation into cheap breathalysers more than 10 years ago and sadly nothing has changed. Websites are littered with cheap breathalysers that claim to be industry-leading but offer the accuracy of a drunkard trying to get their key in the front door. Not only is this annoying, but if you incorrectly blew legal into your breathalyser and then get pulled over by the police, you could get done for drink-driving even if you thought you were fine.
There are good disposable examples that are cheap but these are one-time use products. With anything you want to use more than once it’s better to spend a bit more and look for one that will be accurate and reliable over time.
A timer is a helpful option that some of the more premium examples offer. It will set an alarm that will notify you when you’re (in theory) sober. Perfect if you enjoy one too many the night before. Alcohol readings are also dependant on different factors including temperature, how deeply you breathe and how different countries process the data to get results. The best (and more expensive) breathalysers will factor these all in to get a more accurate result.
What makes a breathalyser accurate?
A breathalyser’s accuracy depends on a mix of sensor quality, calibration, and correct usage. The most reliable models use fuel cell sensors, the same technology found in many police devices, which respond specifically to ethanol and are less affected by other substances. Cheaper units often use semiconductor sensors, which can be less precise and more prone to false readings.
Accuracy also relies on regular calibration – usually every 6–12 months – to ensure the readings match known alcohol concentrations. Even the best device can give incorrect results if not maintained, plus user technique plays a big role:
- Wait at least 20 minutes after eating, drinking, or smoking to avoid ‘mouth alcohol’ skewing results.
- Follow the manufacturer’s instructions for blow duration and pressure.
Environmental factors such as temperature and battery power can also influence readings. Finally, remember that alcohol continues to absorb into the bloodstream for up to 2.5 hours after drinking, so a reading taken too soon can underestimate your true blood alcohol concentration.
What’s the best way to check breathalyser quality?
Look for models with NF approval (French Standard), as these have been independently tested for accuracy. In the UK, there’s no official testing body, so certification from France is a strong indicator of reliability. Choose devices with fuel cell sensors rather than cheaper semiconductor sensors, as they’re more precise and less affected by other substances. Be cautious of vague marketing terms like ‘police-grade’ – without independent testing, these claims are meaningless.
Can mouthwash or mints affect breathalyser results?
Yes. Alcohol-containing mouthwash and breath sprays can skew readings for several minutes by introducing mouth alcohol rather than lung alcohol.
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