Headphone adapters bridge the gap between different plug sizes and connector types, letting you use your favorite headphones with a wider range of devices. Audio-Technica describes two main analog plug formats: the standard 6.3 mm plug and the 3.5 mm mini-plug. Many headphones ship with a 3.5 mm plug and include a 6.3 mm adapter, while some replacement cables come with a screw-on adapter. Many phones now have no headphone jack at all, so adapters also matter if you want to keep using wired headphones. This guide explains the main adapter types, what to look for, and how to avoid common compatibility pitfalls.
Understanding plug sizes: 3.5 mm and 6.3 mm
Audio-Technica’s guide to headphone specs explains that the connector plugs into the headphone jack of AV equipment or portable audio players and comes in two main formats: standard (6.3 mm, also written as 1/4 inch) and mini-plug (3.5 mm). Many headphones are designed with a 3.5 mm plug and include a 6.3 mm adapter in the box, allowing you to connect to both types of jacks.
According to Audio-Technica’s product page for a replacement cable for its monitor headphones, the cable includes a 6.3 mm screw-on adapter. If your headphones came with an adapter, keep it with them. For more on replacement cables, see our replacement headphone cables page.
Adapters for phones without a headphone jack
Many modern smartphones no longer include a 3.5 mm headphone jack. Instead, they rely on digital connections like Lightning or USB-C to output audio. Apple offers two official adapters: the Lightning to 3.5 mm Headphone Jack Adapter and the USB-C to 3.5 mm Headphone Jack Adapter. Apple Support states that the Lightning adapter requires an iOS device with iOS 10 or later. The Lightning adapter is for iPhone, iPad and iPod touch models with a Lightning connector. The USB-C adapter connects 3.5 mm headphones to a USB-C port, though, as the next section explains, not every USB-C adapter suits every phone.
Apple also notes an important behavior: if you connect two headphones to an iOS device using both the 3.5 mm headphone jack and the Lightning connector, audio will play only from the last one you connect. This is useful to know if you frequently switch between wired headphones.
Samsung’s support page explains that newer Galaxy phones have no dedicated 3.5 mm headphone socket and instead use a USB-C converter. Because these devices no longer directly support digital-to-analog conversion, you need a USB-C to 3.5 mm adapter with a built-in DAC. Samsung advises that if you choose an adapter from a different manufacturer, you should always ensure it is DAC compatible.
What is a DAC and why does it matter?
DAC stands for Digital to Analogue Conversion. In simple terms, a DAC converts the digital audio signal from your phone or computer into an analog signal that headphones can reproduce. Samsung explains that its newest models no longer directly support DAC through the USB-C port, so the conversion has to happen in the adapter, and that a 3.5 mm headset that will not work over USB-C may be connected through an adapter that is not DAC compatible. Always check the product description or packaging for “DAC compatible” or “built-in DAC” when shopping for a USB-C adapter.
Remote and microphone compatibility
Even if an adapter passes audio correctly, the inline remote and microphone on your headphones may not work as expected. Apple Support cautions that when you use Apple headphones with earlier Apple products, you might be able to play audio but not use other features. For example, volume or playback control might not function on some iPod models. If remote and microphone functions matter to you, check the adapter maker’s and device maker’s compatibility information for your exact models before you rely on them.
Quick checklist before you buy an adapter
Use this simple checklist to narrow down your options:
- Identify your device’s output port: 3.5 mm, Lightning, or USB-C.
- Know your headphone plug size: 3.5 mm or 6.3 mm.
- If your device lacks a headphone jack, confirm the adapter has a built-in DAC.
- Check whether the adapter supports inline remote and microphone functions for your device.
- For secure connections, consider a screw-on adapter if your headphones support it.
Taking a moment to verify these points can save you from buying an adapter that does not work with your setup. For a deeper look at all the accessories that can improve your listening experience, browse our headphone accessories section and our headphone accessories guide. When carrying adapters, a small case can prevent loss or damage; see our headphone cases page for storage ideas.
Frequently asked questions
Can I use a 6.3 mm plug with a 3.5 mm jack?
The usual adapter works the other way round: it fits over a 3.5 mm plug so the headphones can go into a larger 6.3 mm jack. Audio-Technica notes that many headphones with a 3.5 mm plug include a 6.3 mm adapter. If yours is a screw-on type, thread it on fully.
Do all USB-C to 3.5 mm adapters work with any phone?
Not necessarily. As Samsung’s support page explains, phones that have removed the headphone jack often require an adapter with a built-in DAC. Samsung says its newest Galaxy phones need a USB-C to 3.5 mm adapter with a built-in DAC. Always check the adapter’s specifications for DAC compatibility before buying.
Will my headphone’s remote and mic work through an adapter?
It depends on the adapter and the device. Apple notes that some older products may not support volume or playback controls when using an adapter. Check the manufacturer’s compatibility information for your specific setup.
For more details on adapters and related accessories, visit our headphone adapters page.
