VPN testing - the latest results from our team of experts

Hundreds of hours spent testing the biggest and best virtual private networks (VPNs) have all boiled down to this: the latest VPN rankings in 2024. Our experts have picked apart mobile and desktop apps, speeds, features, security, and most importantly value for money to bring you the best VPN services on the market today.

For six years, ExpressVPN maintained its number one spot thanks to impeccably designed apps, seamless ease of use, and attention to detail that showed perfectionism was at the heart of everything it did. However, with an ongoing cost of living crisis, there's more to consider than just how well the core service performs and how well-built the apps are. 

This time, however, NordVPN finally closed the gap on ExpressVPN thanks to its ever-growing mass of features, reliable content unblocking, and customizable pricing which means you only need to pay for what you want to use.

Read on to find out more about what separates the top VPNs, and how each one compares in our rigorous testing.

Written by
Andreas Theodorou Editor-in-Chief Tech Software
Written by
Andreas Theodorou (MRes, BA)

As a digital privacy advocate and expert, he's spent the past four years leveraging his master's degree to research VPNs, cryptography, and other cybersecurity topics.

The 5 best VPNs in 2024

1. The best VPN on the market today: NordVPN

1. The best VPN on the market today: NordVPN
NordVPN has finally claimed the throne following our latest reviews. Its all-in-one security suite, along with its consistently excellent speeds and unblocking capabilities make it a reliable service, and when you look at the customizable pricing, you're only paying for what you'll use, making it exceptional value for money. 

With built-in features like a password manager, malware protection, ad-blocking, secure storage, and even additional cyber insurance to protect you from scams, you get maximum protection at a more-than-reasonable price. See for yourself with a 30-day money-back guarantee, and make the most of the best VPN without having to risk your cash.

▶ Read more in our full NordVPN review

Swipe to scroll horizontally
NordVPN test results:
AttributesNotesRating
DesignApps have a novelty that provides a more visually entertaining user experience⭐⭐⭐⭐
Ease of useGood for new users, but more work is needed to make it easier to set up advanced configurations⭐⭐⭐
PerformanceOne of the fastest VPNs on the market, maxing out my testing line⭐⭐⭐⭐⭐
UnblockingUnblocked everything we threw at it, every time we tried⭐⭐⭐⭐⭐
Security and privacyA privacy-first approach that's supported with clear investment in improving the security of its apps⭐⭐⭐⭐⭐
Customer supportFriendly, supportive and professional⭐⭐⭐⭐⭐
PriceFantastic value for money⭐⭐⭐⭐
2. The best VPN for beginners

2. The best VPN for beginners
ExpressVPN remains an industry leader, and its one-click connection means you get the safest, fastest connection automatically. It simplifies the complicated processes other apps would need you to do yourself, and all with 24/7 customer support. 

It's a pricier option than most of the competition, but the quality and attention to detail make it perfect for anyone new to VPNs. It even comes with a built-in password manager, a DNS-based ad blocker, and a year of secure storage. All that, and a 30-day money-back guarantee to fall back on if you want to see how it compares to NordVPN or Surfshark.

▶ Read more in our full ExpressVPN review

Swipe to scroll horizontally
ExpressVPN test results:
AttributesNotesRating
DesignElegant and simple, there's no clutter and everything has its place⭐⭐⭐⭐⭐
Ease of useAn automated one-click connect means you get the safest, fastest protection possible—without having to configure it yourself⭐⭐⭐⭐⭐
PerformanceFast enough for streaming, online gaming, and torrenting, with a big focus on low-latency bandwidth⭐⭐⭐⭐
UnblockingConsistently unblocks every site and region we test⭐⭐⭐⭐⭐
Security and privacyExpressVPN's teams are constantly improving the industry, but a recent DNS leak (now fixed) caused a stir⭐⭐⭐⭐
Customer supportAlways available, friendly, and helpful⭐⭐⭐⭐⭐
PriceAn expensive option, but if you want something you can stake your life on, it's worth every penny⭐⭐
3. The best budget VPN: Surfshark

3. The best budget VPN: Surfshark
Once again, Surfshark secures the best cheap VPN title. Much like NordVPN, Surfshark maxed out our speed testing lines, but also blew us away with the fastest OpenVPN speeds we've seen in a good while.  

Couple that with the immense wealth of features on offer, and Surfshark is a VPN that asks for very little while delivering enormously. With an antivirus, alternative ID and email generators, personal data security reports, and even proactive data broker removal tools, you can do more than just protect your privacy, you can start fighting back.

With servers in over 142 locations, you can stream your favorite shows from almost anywhere. Best of all, Surfshark costs as little as $2.29 per month, and it comes with a 30-day money-back guarantee to try it out.

▶ Read more in our full Surfshark review

Swipe to scroll horizontally
Surfshark test results:
AttributesNotesRating
DesignA simple app with a clear layout⭐⭐⭐⭐⭐
Ease of useA comfortable middle-ground between NordVPN and ExpressVPN⭐⭐⭐⭐
PerformanceOne of the fastest providers around⭐⭐⭐⭐⭐
UnblockingAnother full house—Surfshark keeps getting perfect scores in our unblocking tests⭐⭐⭐⭐⭐
Security and privacyA much-improved antivirus tool, but the Windows kill switch can fail under very extreme circumstances⭐⭐⭐⭐
Customer supportSupport site has come a long way⭐⭐⭐⭐
PriceSo much for so little—no one else can match the value⭐⭐⭐⭐⭐
4. The best Linux VPN: Private Internet Access

4. The best Linux VPN: Private Internet Access
Private Internet Access continues to impress me with the depth of customization available. Its dedicated streaming servers are perfect for unblocking your favorite shows.

Despite its average speed, it's still fast enough for torrenting, gaming online, and streaming in 4K. Plus, PIA is one of the only services to ever prove its no-logs policy in court, twice!

With apps for every major platform, including a Linux VPN GUI, it's perfect for the more technically savvy. But don't just take my word for it, make the most of the 30-day money-back guarantee, and see for yourself.

Read more in our full Private Internet Access review

Swipe to scroll horizontally
Private Internet Access test results:
AttributesNotesRating
DesignLots of customization, but could do with some decluttering⭐⭐⭐
Ease of useNot the best for beginners, but great for advanced users⭐⭐⭐
PerformanceGood speeds, but generally average compared to industry leaders⭐⭐⭐
UnblockingDedicated streaming servers and an enormous global network help you unblock anything and everything⭐⭐⭐⭐⭐
Security and privacyThe latest and greatest in VPN tech, and a proven no-logging policy⭐⭐⭐⭐⭐
Customer supportA mass of knowledge online and expert support on-hand at all times⭐⭐⭐⭐⭐
PriceBudget-friendly and offering plenty of features that would normally cost you twice as much⭐⭐⭐⭐⭐
5. The best of the rest: Proton VPN

5. The best of the rest: Proton VPN
Proton VPN reclaimed fifth place thanks to a big improvement in speeds and service unblocking. Maxing out our testing lines and unblocking every streaming site we threw at it.

Proton is best known for its secure email service, Proton Mail, but you can also take advantage of its calendar tool, password manager, and secure cloud storage, all in a single subscription.

With its popular free plan and an array of great features, Proton is an exceptional pick for anyone who's looking to try before they buy. Put the premium plan to the test with a 30-day money-back guarantee.

Read more in our full Proton VPN review

Swipe to scroll horizontally
Proton VPN test results:
AttributesNotesRating
DesignDark and edgy, it's good if you want that "hacker" vibe⭐⭐⭐⭐
Ease of useSimple and clear designs make it good for beginners⭐⭐⭐⭐
PerformanceIncredibly fast WireGuard speeds⭐⭐⭐⭐⭐
UnblockingUnblocked everything we threw at it⭐⭐⭐⭐⭐
Security and privacyAudited and open-source so anyone can verify its claims⭐⭐⭐⭐⭐
Customer supportSupport articles are helpful and usually have plenty of images ⭐⭐⭐⭐
PriceExpensive compared to Surfshark and PIA, but still reasonable⭐⭐⭐

Our latest test results

This round of testing saw some pretty big shake-ups to our best VPN list. NordVPN finally unseated ExpressVPN for first place, and Surfshark still stands strong as our number three pick and the best cheap VPN overall. PIA has maintained its fourth place standing as the best VPN for Linux and torrenting.

IPVanish dropped back down from fifth to seventh place in our rankings, with Proton VPN clawing back to fifth following a big jump in speed and unblocking scores by the big-name brand. PrivadoVPN maintains sixth as our best free VPN.

CyberGhost remains in ninth place due to a series of minor grievances—decent speeds aren't enough to stand out in this competition, I'm afraid. We want to see a lot more from the provider if it wants to remain in the competition.

Last, but not least, Mullvad holds on to tenth place. It's a decent service, and a popular choice for privacy purists, but the clunky apps and lack of unblocking capabilities leave it feeling dated and buried in the shadow of the industry leaders.

Going a step further

It's not just about which VPN provider has the most to offer, it's about maintaining a reliable, high-quality service.

Mike Williams, our lead VPN Tester, puts it best: "A great VPN isn't necessarily about having the longest feature list or the highest possible speeds. What really matters is quality, attention to detail, and the kind of consistency that says not only can you trust this provider with your privacy right now, but you can be confident it'll stay that way for the foreseeable future."

I agree with him—you're not just buying a VPN in the here and now, you're investing in it for the next few years. It's one of the key reasons ExpressVPN held the crown for so long. We had so much confidence in what Express was doing.

However, with ExpressVPN's recent DNS leak issue compounding our anxieties after the Kape layoffs, we knew that NordVPN was the right choice for the top spot this time around. With its enormous wealth of features and fantastic value for money, it had finally overtaken its biggest rival.

Stream unblocking results

VPNs regularly claim they unblock all of your favorite shows, but which ones really do? Check out the results from our testing below to see whether a service can access global streaming services:

Swipe to scroll horizontally
VPN ProviderNetflix librariesUS servicesUK and Australian services
1. NordVPNUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
2. ExpressVPNUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
3. PIA

US, UK, AU, CA, JP

Amazon, Disney

iPlayer, ITV, C4, 9Now, 10 play

4. Proton VPNUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
5. SurfsharkUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
6. WindscribeUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
7. CyberGhostUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now
8. PureVPNUS, UK, AU, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now
9. Hide.meUS, UK, AU, CA

Amazon, Disney

iPlayer, ITV, C4, 9Now, 10 play

10. IPVanishUS, UK, CA, JPAmazon, DisneyiPlayer, ITV, C4, 9Now
11. StrongVPNUS, UK, CA, JPAmazoniPlayer, ITV, C4, 9Now
12. UltraVPNUS, AU, CA, JPAmazoniPlayer, ITV, C4, 9Now
13. PrivadoVPNUS, JPAmazon, DisneyiPlayer, ITV, 9Now, 10 play
14. AtlasVPNUKAmazon, DisneyiPlayer, ITV, C4, 9Now, 10 play
15. Hotspot ShieldUS, CA, JPAmazoniPlayer, ITV, C4, 9Now
16. VyprVPNUS, CAAmazoniPlayer, ITV, C4, 9Now, 10 play
17. PrivateVPNUSAmazon, Disney9Now, 10 play
18. Windscribe (free)US, CADisneyiPlayer, ITV, C4
19. PrivadoVPN (free)US, JPDisneyiPlayer
20. Le VPNUKAmazoniPlayer, ITV, C4, 9Now
21. AstrillUS, UKFailediPlayer, ITV, C4, 9Now
22. FastestVPNUS, JPFailedITV, C4, 9Now, 10 play
23. Whitehat VPNCAAmazon, DisneyC4, 9Now
24. Norton VPNCAFailedC4, 9Now
25. TunnelBearFailedAmazon, DisneyiPlayer, ITV, C4
26. Hotspot Shield (free)FailedAmazon, DisneyiPlayer, ITV, C4
27. MullvadUSFailediPlayer, ITV, C4, 9Now
28. MozillaFailedFailedITV, C4, 9Now
29. Google OneFailedFailedFailed
30. Proton VPN (free)FailedFailedFailed

Malware, tracker, and ad-blocking results

Many VPNs say they have built-in ad, tracker, and malware blocking, and most reviews just take it for granted that these work and deliver useful results. Our lead tester aimed to measure this feature for each provider, and see how they compare to each other.

The tests included the following:

  • A custom tool that attempts to access 156 common trackers (Facebook, Twitter and so on), and records whether it’s still available.
  • A custom tool that tries to access a selection of URLs (300-600-ish) from a daily updated curated list of malicious URLs, like GitHub, and records what happens
  • Running a couple of ad-blocking testers (including AdBlock Tester) and recording the score.

Without further ado, lets see which VPNs give you that little bit extra, and which ones are only offer lip service:

Swipe to scroll horizontally
VPN Provider

Trackers blocked

Malware blocked

Ad blocking score

Atlas

69%

28%3%

CyberGhost

96%

85%80%
ExpressVPNN/A83%69%
FastestVPN57%

87%

41%

Hide.meN/A91%91%
IPVanishN/A79%34%

Mozilla

74%

99%

90%

Mullvad

74%

85%

91%

NordVPN

64%96%51%

Norton

69%

100%

16%

PrivadoVPN

90%

60%74%

PIA

96%

65%81%
Proton VPN

81%

85%75%
PureVPN15%36%N/A

Surfshark

65%

91%3%

Windscribe

94%

100%

93%

Disclaimer

These tests aren't large or precise enough to generalize from them, and only offer insight that the services will provide some additional protection. I would recommend taking the results with a pinch of salt. These built-in features are never a substitute for a dedicated antivirus/security app, and I would recommend using the best antivirus and a reliable ad-blocker to further shore up your security.

When we test the ad blocking capabilities, we were testing using only the app, and not any additional browser extensions as these should operate system-wide. However, it is worth noting that using the browser extension for a provider can greatly increase the level of protection it offers, and some providers, such as Surfshark for example, find their ad blocking capabilities are greatly enhanced through the addition of their browser extensions.

VPN speed testing

It's a well-trodden sales technique for VPN providers to claim they have the fastest speeds—but they clearly can't all be the fastest. That's why we test the speeds on offer from all the top VPNs across different global servers and on a variety of protocols. 

Below are the speed results for the top VPN services, during our latest tests:

Swipe to scroll horizontally
VPN ProviderWireGuard or proprietaryOpenVPN
1. Surfsharkover 950 Mbps (maxed out our testing)640 Mbps
2. Mullvadover 950 Mbps (maxed out our testing)410 Mbps
3. Proton VPNover 950 Mbps (maxed out our testing)400 Mbps
4. Windscribeover 950 Mbps (maxed out our testing)240 Mbps
5. PrivadoVPNover 950 Mbps (maxed out our testing)220 Mbps
6. NordVPNover 950 Mbps (maxed out our testing)110 Mbps
7. Norton VPNover 950 Mbps (maxed out our testing)240 Mbps
8. PureVPN880 Mbps210 Mbps
9. Atlas VPN785 MbpsN/A
10. IPVanish770 Mbps230 Mbps
11. CyberGhost760 Mbps360 Mbps
12. FastestVPN730 Mbps170 Mbps
13. AirVPN710 Mbps300 Mbps
14. Hide.me690 Mbps210 Mbps
15. Hotspot Shield600 MbpsN/A
16. VyprVPN590 Mbps145 Mbps
17. TunnelBear480 Mbps180 Mbps
18. ExpressVPN410 Mbps210 Mbps
19. StrongVPN395 Mbps210 Mbps
20. Astrill VPN390 Mbps (unstable speeds)N/A
21. Private VPN350 Mbps125 Mbps
22. Private Internet Access330 Mbps270 Mbps
23. Mozilla VPN360 MbpsN/A
24. Google One345 MbpsN/A
25. UltraVPN300 MbpsN/A

TechRadar's VPN rankings

There are hundreds, if not thousands of VPNs out there, and you've likely heard the names of countless services. Check out our rankings below of popular services and see some honorable mentions that can't currently compete with what's on offer with our top services.

Swipe to scroll horizontally
VPN serviceRatingSummaryReviews
1. NordVPN⭐⭐⭐⭐½The best VPN overall, it's perfect for streaming, gaming, and even comes with a whole security suiteCheck out our NordVPN review
2. ExpressVPN⭐⭐⭐⭐½The best VPN for beginners, and great for streaming contentCheck out our ExpressVPN review
3. Surfshark⭐⭐⭐⭐½The best cheap VPN, and also the fastest in our testsCheck out our Surfshark review
4. Private Internet Access⭐⭐⭐⭐½The best Linux VPN with a dedicated GUI for Linux, and a no-logs policy that was proven in court twiceCheck out our Private Internet Access review
5. ProtonVPN⭐⭐⭐⭐A popular free VPN service with a history of advocating for the freedom of the internetCheck out our Proton VPN review
6. PrivadoVPN⭐⭐⭐⭐The best free VPN—it even unblocks NetflixCheck out our PrivadoVPN review
7. IPVanish⭐⭐⭐⭐An up-and-coming provider that supports LinuxCheck out our IPVanish review
8. Windscribe⭐⭐⭐⭐A fast service with a popular browser proxyCheck out our Windscribe VPN review
9. CyberGhost VPN⭐⭐⭐⭐A popular and easy-to-use platform that's great for beginnersCheck out our CyberGhost VPN review
10. Mullvad⭐⭐⭐⭐Good for Linux, and you can even pay in cashCheck out our Mullvad review
11. PureVPN⭐⭐⭐⭐One of the cheapest premium VPNs on the marketCheck out our PureVPN review
12. Hide.Me⭐⭐⭐⭐A speedy service with plenty of customizationCheck out our Hide.me review
13. Atlas VPN⭐⭐⭐½A new player in the VPN industry that's already making wavesCheck out our Atlas VPN review
14. TunnelBear⭐⭐⭐½A reliable free VPN but no support for content unblockingCheck out our TunnelBear review
15. Mozilla VPN⭐⭐⭐½A well known brand with a VPN that currently underperformsCheck out our Mozilla VPN review
16. Hotspot Shield⭐⭐⭐½A fast VPN service with lots of great featuresCheck out our Hotspot Shield review
17. VyprVPN⭐⭐⭐½A reliable VPN with a dedicated protocol for bypassing even the most severe censorshipCheck out our VyprVPN review
18. Norton VPN⭐⭐⭐Known for its popular security suite with a lacklustre VPNCheck out our Norton VPN review
19. PrivateVPN⭐⭐½An excellent cheap service that offers plenty of support for streaming and torrentingCheck out our PrivateVPN review
20. AstrillVPN⭐⭐½A mid-range VPN that's popular for bypassing Chinese censorshipCheck out our Astrill VPN review
21. FastestVPN⭐⭐½Making its way up the list, but not yet living up to its nameCheck out our FastestVPN review
22. StrongVPN⭐⭐Another mid-range VPN that continues to improveCheck out our StrongVPN review
23. AirVPN⭐⭐Built by hacktivists, for hacktivistsCheck out our AirVPN review
24. Goose VPN⭐⭐An incredibly cheap mid-range VPNCheck out our Goose VPN review
25. TorGuard⭐⭐A torrent-friendly VPN that's good for accessing foreign contentCheck out our TorGuard review
26. UltraVPN⭐⭐Fast and secure with plenty of server locationsCheck out our UltraVPN review
27. Le VPN⭐⭐Lots of locations to choose from and integrated SmartDNS technologyCheck out our Le VPN review
28. VPNArea⭐⭐A mid-range VPN that struggles to hold up against the industry leadersCheck out our VPNArea review
29. ZoogVPN⭐⭐A fairly underwhelming VPN from GreeceCheck out our ZoogVPN review
30. Google One⭐⭐Google's history with and general approach to your data doesn't give us much faith in the serviceCheck out our Google One VPN review

How we test VPN services - our review methodology

While our experts use the top VPNs every day, we conduct a comprehensive analysis of the top 30 VPN services every 6 months with the help of Mike Williams and Anthony Spadafora. This allows us to keep track of who's really the best, and for which use cases.

TechRadar's VPN reviews begin at the provider's website, where we analyze the claims it makes, its privacy policy, its support options, and any other elements of note. We look for any tracking cookies on the site and if/when they activate to see if the service tracks people using the site.

Next, we ask ourselves the following questions: what security tools does the provider offer? Does it promise the world, or is it more realistic? Does the privacy policy clearly say how your data is handled? Are there any catches in the small print? Is the pricing open and honest? Ultimately, we're considering not just what the provider says it gives you, but what it really gives, and whether you can trust it with your data.

We don't take a service at face value

There's more to a VPN than just what its marketing says. Where possible, we try to go behind the curtains and look at what's really going on and doing our own testing to see whether the apps really work as claimed.

In order to make sure our reviews are as honest and realistic as possible, we make every effort to sign up for the services anonymously, so our results aren't skewed by the services knowing they're being tested by us.

After signing up for a plan, we install and test the Windows, Mac, Android, iOS, and Linux VPN apps, as these are the most popular platforms. Then, we move on to testing the features within those apps, like the kill switch, checking for data leaks, and generally confirming everything works as advertised.

As we do this, we play around with the different encryption protocols on offer, connect to different servers, throw malware at it, and generally look for any way we can stress test the service. If anything breaks under any of our tests, we report it back to the provider so they can fix the issue, but we make sure to include both the issue and the provider's response in our results where appropriate.

We test every VPN provider's speeds at least 120 times across two sessions, and use both a US home connection and a 1 Gbps UK data center to show us a provider's potential versus the real-world application. We measure using different encryption protocols, speed test websites, and features and use the average of the best session as the provider's peak speed. In doing so, you get a better understanding of what you can really expect when you use the service, and not just an arbitrary figure of its fastest speed.

nPerf performance benchmark for VPNs testing a VPN server in London

Our VPN speed testing in progress (Image credit: nPerf)

A good VPN should be able to unblock multiple streaming services. To check this, we try to access geo-exclusive content from Netflix, Amazon Prime Video, Disney Plus, and BBC iPlayer, repeating the test from three different locations around the world to get an idea of how the service performs in real life.

In our day-to-day testing, we take a more focused approach depending on the needs of the specific use cases we're writing about. Such as how easy it is to set up the VPN, how much attention to detail there is in the design, and whether a beginner can pick it up easily. We carry out constant real-world testing to make sure our analysis is always accurate and relevant.

However, I don't just trust what I see on the surface of a VPN provider's website. I'll take a peek behind the curtains of the software—view the contents of its RAM, even decompile and browse its source code (if I can) just to find out what's going on under the hood. Ultimately, I want to know whether the service gives you genuine protection or just a false sense of security.

Want to know more about how we test VPNs? We have a much more in-depth explanation on our VPN testing methodology page.

Our VPN testing panel

Meet the experts behind our VPN deep dives:

Andreas Theodorou Editor-in-Chief Tech Software
Andreas Theodorou

A privacy purist at heart, Andreas is a VPN expert that believes that the best VPN doesn't have to be the most expensive—it's about what's right for you.

Anthony Spadafora
Anthony Spadafora

Anthony helps us test real-world VPN speeds in the US so we get a more accurate view of what a service is really like to use around the world. 

Mike Williams in the dark
Mike Williams

Mike regularly reviews our top picks, and loves looking behind the curtains to see how a VPN works in the background. If there's a skeleton in the closet, he'll find it.

Mo Harber-Lamond, VPN Editor for Future PLC
Mo Harber-Lamond

One of our leading VPN experts, Mo tests VPN services every day to see what providers say they do, and what it's really like as a day-to-day user.

Disclaimer

We test and review VPN services in the context of legal recreational uses. For example:

1. Accessing a service from another country (subject to the terms and conditions of that service).

2. Protecting your online security and strengthening your online privacy when abroad.

We do not support or condone the illegal or malicious use of VPN services. Consuming pirated content that is paid-for is neither endorsed nor approved by Future Publishing.

Andreas Theodorou
Editor-in-Chief of Tech Software

Andreas has been with TechRadar as Future PLC's Editor-in-Chief of Tech Software since March 2023, supporting content and teams on VPNs, antivirus, and other cybersecurity tools. He's previously written for and led content at ProPrivacy, Business2Community, and The Tech Report. After completing a Master of Research degree, Andreas fell in love with all things cybersecurity; combining his passions to help expose the prevalence of ad tech in the charity sector and raise awareness of digital privacy around the world.

With contributions from