Blog

What Is a PUK (Personal Unblocking Key)?

16.01.2026 | Reading time: 3 minutes

The PUK code usually comes into play when nothing works anymore: no calls, no texts, and no mobile data. After entering the wrong PIN too many times, your SIM card gets locked and without the correct PUK, your phone stays offline. But what exactly is a PUK, what is it used for, where can you find it, and what happens if it gets blocked?

In this blog, you’ll find out how the PUK works, when you need it, and which steps help you unlock your SIM quickly and safely.

Unlock Your yallo SIM Card: PIN & PUK Guide

08.01.2026 | Reading time: 3 minutes

If you’ve forgotten your SIM PIN or entered it incorrectly too many times, don’t worry – your yallo SIM card can usually be unlocked. This guide explains where to find your SIM PIN and PUK, what happens after repeated wrong attempts, and how to get back online fast.

How can I protect my phone from hackers?

19.12.2025 | Reading time: 7 minutes

Your smartphone is your daily companion: messages, photos, banking, emails, social media, maybe even health data. That’s exactly why it’s interesting for hackers too. Sometimes, all it takes is an unwary tap, an unsafe download or an open Wi-Fi network – and attackers have found a way in. The good news: with a few simple habits, you can protect your phone well against hackers, without having to deal with technical details every day. But which settings really matter, and how can you stay safer in everyday life?

Setting up a Wi-Fi connection for phone and PC

19.12.2025 | Reading time: 6 minutes

Whether you’re at home, in the office or staying in a hotel: these days, almost nothing works without Wi-Fi. Your smartphone, laptop or smart TV needs a stable Wi-Fi connection so that streaming, video calls and browsing run smoothly. But how do you actually set up a Wi-Fi connection correctly – on your phone and on your PC? In this guide, we show you step by step how to connect your device to a Wi-Fi network, which settings matter and what you can do if the connection doesn’t work straight away. You’ll also get a few tips on security and speed so that your Wi-Fi not only works, but is also reliable and protected.

What is a metered connection?

18.12.2025 | Reading time: 5 minutes

You’re on a train with your laptop, using your phone’s hotspot data, and suddenly half of your monthly data pass is already gone. Or at home you have an internet connection with a limited data allowance. Exactly for situations like these, Windows offers a setting called “metered connection”. But what is a metered connection, what does Windows do with it, how do you set it up and when is this feature really useful? That way you don’t just know what metered connections are, you can also use them deliberately in everyday life to save data.

Google Pay made simple

17.12.2025 | Reading time: 5 minutes

Paying with your smartphone, without a wallet – for many people in Switzerland, that’s already part of everyday life. One of the best-known services for this is Google Pay. But what exactly is Google Pay, how does mobile payment with it work, and what should you watch out for if you want to use the service?

Which browsers are there?

16.12.2025 | Reading time: 6 minutes

You open your browser almost automatically: email, news, online banking, streaming – everything runs through this one programme. But if someone asks you which browsers actually exist, you might only think of one or two names. In fact, the choice is much bigger, and the differences are more important than you might think. Find out which internet browsers there are, how they differ and which browser suits your everyday life, whether you use Windows 10, still use Windows 7, macOS or mainly your smartphone.

How to connect your smartwatch to your phone: step-by-step guide

09.12.2025 | Reading time: 11 minutes

A smartwatch brings your smartphone right to your wrist: notifications, calls, fitness data, navigation and music control become accessible without taking your phone out of your pocket. For everything to work smoothly, the watch and smartphone must be paired correctly.

Phone battery: How long it really lasts

03.12.2025 | Reading time: 10 minutes

Modern smartphones almost always use lithium-ion batteries. They are powerful and compact, but they wear out with every charging cycle and with every exposure to heat. In this article, you’ll learn how long a phone battery lasts on average, what influences phone battery lifespan, how long a Samsung phone battery typically holds up, and what you can do to extend battery lifespan.

What are cookies?

02.12.2025 | Reading time: 7 minutes

Cookies are everywhere when you browse the web. They help websites recognise you, for example for login, to save settings and to keep items in your shopping cart. At the same time, however, they also pose risks to privacy and the tracking of your online behaviour. But how do cookies work in the browser, what types are there, what opportunities and risks do they involve and how can you manage cookies on your devices?

Which yallo Black mobile plans suit me?

26.11.2025 | Reading time: 9 minutes

Choosing the right mobile plan today determines not only how fast you surf in Switzerland, but also how relaxed you are when travelling. With the yallo Black mobile plans you get a plan that covers both everyday life and holidays at the same time. The plans have recently been significantly upgraded: you now get roaming in 49 additional countries, and the price remains the same. If you’d like to get familiar with the technical basics of roaming, the country categories and the related costs, you can find everything in our dedicated guide Roaming abroad.

What is Replay TV?

20.11.2025 | Reading time: 7 minutes

Digital television has changed the way you consume programmes. With the Replay function, you can watch shows that have already aired whenever it suits you. This form of time-shifted television has transformed the daily habits of many viewers but also raises economic and legal questions. So how do Replay services work in Switzerland, what changes have been introduced in recent years, and how can you make the most of the offer?

What is the cloud?

19.11.2025 | Reading time: 7 minutes

The cloud is something you already use every day, even if you do not think about it. But what exactly does cloud computing mean? You’ll learn what the cloud is, how it works, what benefits it offers and what to look out for when using it, both privately and in business.

Phone overheating: Reasons and solutions

12.11.2025 | Reading time: 8 minutes

An overheated phone is a common issue, especially on warm days or during intensive use. If your phone gets hot while charging, gaming or making calls, you’ll quickly notice that something isn’t right. Excessive temperatures can not only shorten battery life but, in the worst case, also cause hardware damage. The good news: in most cases, you can easily prevent or fix overheating.

AirDrop not working? Here’s how to fix it

04.11.2025 | Reading time: 5 minutes

AirDrop is super convenient: quickly send photos, videos, contacts or documents between iPhone, iPad and Mac, no cables or messaging apps needed. But what if it suddenly stops working? Don’t panic. In this guide, you’ll find clear, easy-to-follow instructions on how to systematically fix AirDrop issues, from a quick 2-minute check to more advanced settings on iOS, iPadOS and macOS. You’ll also get practical everyday tips to keep your wireless transfers running smoothly.

The history of Black Friday

28.10.2025 | Reading time: 4 minutes

Black Friday has transformed from an American tradition into a global shopping event like no other. Originating in the United States after Thanksgiving, it now stands for discounts and deals that attract millions worldwide. In the following paragraphs, we’ll dive into its fascinating origins and explore how Black Friday grew from a national event into an international shopping sensation.

Roaming abroad: countries, costs and tips for your travels

28.10.2025 | Reading time: 7 minutes

Anyone travelling abroad wants to use their smartphone as naturally as at home – for browsing, calling, navigating or quickly sending messages. While flat rates are often standard in Switzerland, unexpected costs can quickly arise abroad. The reason for this is roaming: your phone automatically connects to a foreign network, and the charges are billed through your provider.

What is a firewall?

23.10.2025 | Reading time: 5 minutes

A firewall is the digital bouncer between your device or home network and the internet. It monitors all data traffic and decides, based on predefined rules, which connections are allowed, and which are blocked. In this way, unwanted access, insecure services and attacks can be effectively contained, without you having to give up everyday convenience.

How to pay with your smartphone in Switzerland?

21.10.2025 | Reading time: 3 minutes

Paying by phone in Switzerland has become part of everyday life. Whether you’re in a supermarket, shopping online, or paying for services, technologies like NFC, QR codes, and mobile wallets make contactless payments quick and simple. This guide explains what mobile payment is, how it works, which providers in Switzerland are available, how secure it is, and what to keep in mind when setting it up and using it every day.

Secure password: how to create, check, and manage strong passwords

16.10.2025 | Reading time: 4 minutes

A strong password is your best defense against account takeover. Learn why a secure password matters, how many characters it should use, which methods work best, how to use a password manager, and how to secure your Wi-Fi with a robust key.

Why is my hotspot not working?

14.10.2025 | Reading time: 6 minutes

If your hotspot isn’t working, the cause usually comes down to a handful of easy fixes: wrong settings, power-saving mode, an incompatible band, or a plan that restricts tethering. Follow the right sequence and you can typically get iPhone hotspot or Android hotspot running again in minutes.

What is a server and how does it work?

09.10.2025 | Reading time: 6 minutes

A server provides other devices or applications with services, data, and computing power. It can operate on a home network, within a company network, or on the internet. It’s important to distinguish between the server software (the programs and services it runs) and the physical server (the hardware). Both meanings are correct and widely used.

Internet very slow despite high speed?

07.10.2025 | Reading time: 5 minutes

It is annoying when your device shows “full bars” and the connection seems stable, but websites only load slowly, videos stutter, or a download seems to take forever. A strong Wi-Fi signal does not automatically mean high speed. Often the problem does not lie with the provider, but with local factors in your home network.

What is an RFID chip?

02.10.2025 | Reading time: 7 minutes

RFID stands for Radio Frequency Identification. An RFID chip stores a small amount of data and transmits it wirelessly to a reader. You can find this technology in access cards, contactless payment cards, logistics labels, libraries, ski lift tickets, pet microchips and even in the e-passport.

Phone dropped in water — how to save your smartphone from water damage

25.09.2025 | Reading time: 6 minutes

One moment of inattention and the phone is in the water. Whether it’s the sink, bathtub, pool or even the toilet, liquid inside the device can quickly cause short circuits and later corrosion. The good news: with the right steps you can still save a lot.

Safe browsing on the internet: protect yourself and your data

18.09.2025 | Reading time: 7 minutes

Whether it’s shopping, e-banking or streaming, the internet is part of your daily life. Every action leaves traces, and many underestimate how quickly personal data can be misused. With the right settings, tools and habits, you’ll browse more safely, protect your privacy, and significantly reduce the risk of cybercrime.

What is NFC and how does it work on your smartphone?

08.09.2025 | Reading time: 5 minutes

NFC (Near Field Communication) is a wireless communication technology that lets you transfer data over very short distances, usually just a few centimeters, securely. You probably use it every day without noticing: contactless payments with your phone or quick pairing of devices.

How to stay connected to the internet while traveling?

28.08.2025 | Reading time: 7 minutes

Whether it’s a weekend getaway, summer holiday or workation, nowadays, going on holiday without mobile internet is almost unthinkable. Navigation, hotel check-in, translations, streaming or social media: you want to stay flexible, connected and avoid any nasty surprises on your bill.

What is an eSIM?

27.08.2025 | Reading time: 6 minutes

The eSIM is a modern evolution of the traditional SIM card and is revolutionising the way you use mobile services. Instead of inserting a physical card into your smartphone, the eSIM is stored directly on the device and can be activated digitally.

No signal on TV: What does it mean and how to fix it?

25.08.2025 | Reading time: 6 minutes

Suddenly your TV only shows “No signal”? The screen stays black, the remote control doesn’t help, and your evening of binge-watching seems ruined. But don’t worry – such issues are usually harmless and can be resolved with a few targeted steps.

What is streaming TV and how does it work?

22.08.2025 | Reading time: 3 minutes

In Switzerland, many households have already replaced traditional TV connections with Streaming TV. No need for cables or satellite dishes, all you need is an internet connection and a compatible device. But what exactly is streaming TV, how does it work, and why are so many people switching?

5G simply explained

01.08.2025 | Reading time: 6 minutes

With 5G, a new era of mobile communication begins. The fifth generation of mobile technology promises not only significantly higher speeds, but also extremely low latency and the ability to connect millions of devices simultaneously. But what does that actually mean for you? What is 5G internet, how does it work, and how is it different from 4G? In this overview, you’ll find clear and simple answers to all the key questions about this new standard.

Transfer data to a new phone: how to make the switch

25.07.2025 | Reading time: 5 minutes

A new phone is always exciting: better camera, faster processor, more storage. But before you can really start using your new smartphone, one important question arises: how do you get all your data from the old phone to the new one?

What is roaming?

18.07.2025 | Reading time: 5 minutes

Are you planning your next adventure abroad, but unsure about using your mobile data while traveling? Data roaming is a concept that often confuses travelers, but fear not!

Connect and cast your phone to the TV

11.07.2025 | Reading time: 5 minutes

Today, the smartphone is our constant companion – for photos, movies, music, games, or presentations. But sometimes, the small screen just isn’t enough. The good news: you can easily connect your phone to the TV – and enjoy content in a large and convenient format. There are various options for doing this, depending on whether you’re using an Android phone, an iPhone, a Smart TV, a Fire TV Stick, or a traditional TV. Whether wireless or with a cable – here’s how it works.

Setting up a new phone: step-by-step guide

04.07.2025 | Reading time: 6 minutes

Starting a new smartphone is always exciting. But before you can fully dive in, there's a setup process where you configure your device properly, secure your data, and get everything ready for everyday use. This guide walks you through the key steps to ensure your new smartphone is ready to use quickly and that no data is lost.

The history of the mobile phone: from the first mobile to today

27.06.2025 | Reading time: 7 minutes

Today, your mobile phone is your constant companion – you use it to make calls, send messages, take photos, navigate, play games and even work. But how did it all start? Just a few decades ago, making a call while on the go was a futuristic dream. Since then, the mobile phone has evolved from a bulky gadget for tech enthusiasts into a digital all-rounder you can’t imagine your daily life without. The history of the mobile phone is a story of invention, competition, miniaturisation and constant transformation.

Watching TV over the internet

13.06.2025 | Reading time: 6 minutes

TV has changed fundamentally in recent years. Instead of relying on traditional cable or satellite, more and more people are turning to internet-based television. With modern technology, you can now watch TV via Wi-Fi—without complicated installations or expensive equipment. All you need is a stable internet connection and the right TV streaming app.

No signal? here's what to do when your phone has no connection

06.06.2025 | Reading time: 6 minutes

No reception, no internet, no calls - when your phone has no signal, it’s more than just annoying. In a world where we always want (or need) to stay connected, it can feel isolating in those moments.

In Switzerland, the mobile network is generally well developed. Still, there are situations where your device simply won’t connect. Sometimes it's due to your location, sometimes it’s a technical issue, and other times it’s just a setting you’ve overlooked. The good news is: in most cases, the problem can be solved without much effort.

WiFi Calling in Switzerland: pros and cons of wifi telephony

30.05.2025 | Reading time: 5 minutes

Whether you live in a mountain village, work in a modern office building, or are simply sitting in your living room, there are always situations where the mobile signal is weak or completely unavailable. In a country like Switzerland, known for its Alpine landscapes and challenging terrain, this happens more often than you might think. But luckily, there’s a modern solution: WiFi Calling—also known as WLAN Call or simply calling over WiFi.

How to change the SIM card?

23.05.2025 | Reading time: 5 minutes

If you've just picked up a new smartphone, lost your previous device, or switched mobile providers, you'll eventually need to change your SIM card. This is especially important if you're using an iPhone or replacing a prepaid SIM. The good news? Swapping your SIM card is a quick and easy process – as long as you know the right steps to follow. Here’s how to change your SIM card safely, quickly, and without losing any of your data.

What is a smartwatch?

19.05.2025 | Reading time: 7 minutes

A smartwatch is a digital watch with smart features that connects to your smartphone or operates independently using a SIM or eSIM. It allows you to receive notifications, track your fitness, answer calls, read messages, and even make payments on the go.

What internet speed do I need?

16.05.2025 | Reading time: 4 minutes

The demands on home internet connections are growing fast. Whether you're working from home, streaming series in 4K, gaming online, or simply browsing daily, having the right internet speed is key to ensuring your digital life runs smoothly.

What is a hotspot?

09.05.2025 | Reading time: 5 minutes

A hotspot is a wireless access point that allows you to connect to the internet through a Wi-Fi network. In today’s increasingly mobile world, a hotspot is especially useful when no traditional Wi-Fi connection is available – for example while traveling, on a train, in a café, or in public spaces.

What is my IP?

02.05.2025 | Reading time: 6 minutes

Every device connected to the internet—whether it’s your computer, smartphone, or smart TV — is automatically assigned what’s known as an IP address. This address is essential for data exchange across the web and acts like a digital house number. Without it, websites, servers, or online services wouldn’t know where to send the data you’ve requested.

What is a prepaid SIM card?

18.04.2025 | Reading time: 4 minutes

Whether it’s for a smartphone, a second home, or for kids, prepaid SIM cards are a flexible solution for anyone who wants full control over their mobile costs. But what exactly is a prepaid SIM card, how does it work, and how is it different from a traditional mobile plan? In this article, we’ll explain everything you need to know – clearly and with a focus on the Swiss market.

Wi-Fi not working?

11.04.2025 | Reading time: 5 minutes

A stable Wi-Fi connection is essential today—whether for working from home, streaming your favorite content, or staying in touch with friends and family. That’s why it’s incredibly frustrating when your Wi-Fi suddenly stops working. But don’t worry: in most cases, Wi-Fi problems can be fixed with just a few simple steps. In this guide, we’ll walk you through the most common reasons your Wi-Fi might not be working, and give you practical solutions to help you get back online quickly.

What is a VPN and how does it work?

04.04.2025 | Reading time: 5 minutes

The digital world brings countless opportunities—but also some risks, especially when it comes to privacy, security, and online freedom. Today, internet users don’t just want fast browsing—they also want to stay safe and anonymous. A VPN, or Virtual Private Network, offers an effective solution for exactly that. But how does a VPN actually work, and why is it becoming increasingly popular?

Who invented the internet? History & Key facts

31.03.2025 | Reading time: 5 minutes

Today, the internet is an essential part of everyday life — we work, communicate, learn, and entertain ourselves online. But who actually invented the internet? And how did a military research project evolve into a global communications network? In this article, you’ll discover the key milestones, innovations, and pioneers behind the development of the internet. It’s a story of international collaboration, technological breakthroughs, and a profound transformation in how people exchange information.

What’s better: DSL or cable?

07.03.2025 | Reading time: 5 minutes

Looking for a fast and stable internet connection? The question then arises: cable or DSL – which technology is best for you? Both have unique advantages depending on where you live, how you use the internet, and what speed you need.

What is 5G home internet?

14.02.2025 | Reading time: 4 minutes

5G home internet is a next-generation wireless broadband service that delivers high-speed, low-latency internet access using the latest advancements in mobile technology.

Improve your WI-FI Signal

16.11.2024 | Reading time: 3 minutes

There is no better feeling than having a smooth internet connection at home. Stay with us if you want to find out how you can improve your WI-FI signal at home very easily.

fun travel tips

29.07.2024 | Reading time: 3 minutes

Here are some fun travel tips to make your journeys smoother and more exciting. And as a yallo Member, you’ve got a little extra magic for your trips!

Streaming Platforms

21.05.2024 | Reading time: 3 minutes

Are you a film lover or series junkie? We show you the most popular streaming platforms in Switzerland with tips and tricks!

Improve your WI-FI Signal

22.04.2024 | Reading time: 1 minute

Wi-Fi Calling allows you to achieve this, even with limited mobile reception, by utilizing an existing Wi-Fi network.

Battery hacks for your Android Phone!

02.11.2023 | Reading time: 3 minutes

The performance of your battery depends on several factors: the model, your usage, the age of your Phone and much more. But with a few simple settings you can already save battery.

Battery hacks for your iPhone!

25.07.2023 | Reading time: 3 minutes

The performance of your battery depends on several factors: the model, your usage, the age of your iPhone and much more. But with a few simple settings you can already save battery.

What is 5G?

18.04.2023 | Reading time: 3 minutes

5G is more reliable, faster, and better. So you can stay connected at any time and without any problems even when you’re in busy places like festivals or concerts.