How We Research
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want to share one audio source with a friend — music, a movie, a call, both hearing and talking — choose IIISOGNO 3.5mm; if you need to plug wired headphones into a phone or tablet that no longer has a headphone jack, choose aginize 2.
These two adapters look similar in a search results page and do completely different jobs. One splits a single 3.5mm jack into two; the other converts a USB-C port into a 3.5mm jack. Buying the wrong one is an easy mistake, so let's separate them cleanly.
• IIISOGNO 3.5mm biggest strength: two TRRS female ports that both carry full audio and mic, so two people can listen and talk at once from one device.
• IIISOGNO 3.5mm biggest trade-off: it's a splitter, not a converter. If your phone has no 3.5mm output, this cable has nothing to plug into.
• aginize 2 biggest strength: it turns a USB-C port into a working 3.5mm headphone jack — the fix for jackless phones, tablets and laptops.
• aginize 2 biggest trade-off: it's a one-person, one-headphone solution. There's no mic-sharing, no second port, and nothing to split.
• Pick IIISOGNO 3.5mm if you're sharing audio with someone next to you.
• Pick aginize 2 if you just want your old wired headphones to work on a USB-C device.
The IIISOGNO 3.5mm is a 1-foot TRRS splitter with one male plug and two female jacks. The important detail is that both female ports are TRRS, which means each one carries stereo audio and microphone signal. That's what separates it from the cheap splitters that only duplicate sound. Plug a TRRS headset with a built-in mic into each side and two people can listen to the same thing and both be heard on a call or in a game chat. The braided nylon cable is short by design — 1 FT, roughly 30 cm — so it's meant to sit between two people who are already close together, not to stretch across a room. The housing is aluminum, which keeps the connector protected, and the plug is gold-plated, a detail aimed at reducing signal loss at the contact point. It comes as a 2-pack, so you can leave one in a bag and one at a desk.
Who should buy it: couples watching a movie on a laptop with two headsets, friends on a long flight sharing one tablet, families on a road trip, or anyone doing co-op gaming who wants both players on the same audio and mic. It's also a sensible pick if you own TRS headphones or speakers without a mic — the sheet notes those still work, but for sound only, since mic passthrough requires a TRRS plug with a built-in mic.
Who should skip it: anyone whose source device has no 3.5mm output at all. A splitter needs a jack to split. If your phone is USB-C-only, this is the wrong tool — go read the next section. Skip it too if you only ever listen alone; there's no benefit to a second port you never use.
The aginize 2 is a USB-C to 3.5mm audio adapter, sold as a 2-pack, in white. Its job is narrow and useful: it gives a USB-C device a headphone jack. The listing names iPhone 17/16/15 Pro Max Plus, iPad, and Galaxy S26/S25/S24/S23 among compatible devices, plus "and more USB C audio devices" — so the rule of thumb is simply that your device has a USB-C port and you want to plug in wired headphones. The connector type is USB Type C on one end, a 3.5mm headphone jack on the other. Physically it's tiny — roughly 0.39 x 0.39 x 0.39 inches — which means it lives on the end of your headphone cable without adding bulk, and it needs no power of its own. There's no plug, no battery, nothing to charge. It's a passive little dongle you keep attached to your headphones so it's always there when you need it.
Who should buy it: anyone who upgraded to a phone or tablet without a headphone jack and still prefers wired headphones — for the sound, for the lack of charging, or simply because their good pair is wired. Also useful on a USB-C laptop where the single 3.5mm port is already taken, or as a spare to leave in a bag, a car, or a desk drawer. Two in the pack makes that easy.
Who should skip it: anyone who needs two people to share one audio stream, or anyone who needs mic sharing across two headsets. The aginize 2 is a one-in, one-out adapter. It also won't help a device that only has Lightning or a full-size USB-A port — it's USB-C in, 3.5mm out, nothing else. And if your device already has a headphone jack, you don't need this at all.
• Best for sharing audio with a second person → IIISOGNO 3.5mm. Two TRRS ports, both carrying sound and mic.
• Best for sharing a mic on a call or in game chat → IIISOGNO 3.5mm. Both ports support mic, not just audio.
• Best for a phone or tablet with no headphone jack → aginize 2. That's the entire point of the adapter.
• Best for wired headphones on a USB-C laptop → aginize 2. Plug it in, no setup, no power.
• Best for travel and small bags → aginize 2. At roughly 0.39 inches cubed, it disappears into a pocket; the IIISOGNO's 1 FT cable is the more noticeable of the two.
• Best for a fixed two-person setup at a desk or on a couch → IIISOGNO 3.5mm. The short braided cable is sized for exactly that.
• Best if you're unsure what your device has → check the port first. If it has 3.5mm, buy IIISOGNO. If it has USB-C only, buy aginize 2.
• Best for keeping a spare on hand → both. Each ships as a 2-pack, so either way you get a backup.
For most people reading this, the honest answer is that these aren't competitors — they solve different problems, and the right one is decided by your ports, not your preferences. That said, if I had to pick one to recommend without knowing your device, I'd lean toward the aginize 2, because a missing headphone jack is a problem far more people run into in 2026 than a missing audio splitter. If you already have a 3.5mm jack and want to share it, the IIISOGNO 3.5mm is the better buy and the more capable of the two for that specific job. Check the current price on Amazon before you commit, and match the product to your port.
FAQ
Not directly. It needs a 3.5mm output to plug into. If your phone is USB-C-only, you'd need a USB-C to 3.5mm adapter like the aginize 2 first — and even then, the splitter shares whatever single jack you feed it.
No. It's a single USB-C to 3.5mm adapter with one output. For two listeners sharing one source, the IIISOGNO 3.5mm is the correct product.
The aginize 2, provided your device has USB-C and no headphone jack. If your device still has a 3.5mm jack, you don't need either adapter — plug your headphones straight in.
No. The aginize 2 lists no plug and no battery, and the IIISOGNO is a passive cable. Both work without power.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.