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The iPhone 6s and iPhone 6s Plus looked almost identical to the iPhone 6 generation, but they were far more than cosmetic refreshes. Apple added the A9 processor, 2GB of RAM, faster storage, substantially better cameras, stronger aluminum, faster Touch ID, improved wireless hardware and pressure-sensitive 3D Touch. AnandTech’s November 2, 2015 review found them among the fastest smartphones available and awarded an Editors’ Choice Gold recommendation (AnandTech final assessment).
That launch verdict does not transfer unchanged to 2026. Apple’s latest verified security release for the line is iOS 15.8.8, released May 11, 2026; the phones cannot run iOS 16 or later. Today, a 64GB or 128GB unlocked example with a healthy battery can still work as an inexpensive basic or backup phone, but it is a poor choice for anyone needing modern apps, 5G or a long software runway.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
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Apple iPhone SE 3rd Gen, 64GB, Midnight - Unlocked (Renewed) | $120.00 | Buy on Amazon |
| 2 |
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Apple iPhone SE 2nd Generation, US Version, 64GB, Black - Unlocked (Renewed) | $91.50 | Buy on Amazon |
| 3 |
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Apple iPhone 7 32GB Unlocked AT&T/T-Mobile - Silver | $89.75 | Buy on Amazon |
Quick verdict
- 2015: A genuinely substantial “S” upgrade with class-leading performance, much better cameras and a useful—if poorly explained—new interaction model.
- 2026: Consider one only for calls, messaging, music, navigation, light browsing or backup use. Buy condition and compatibility, not nostalgia.
- Best configuration: An unlocked 64GB or 128GB phone with a verified battery, a return window and confirmed carrier support.
- Avoid: 16GB units, Activation-Locked devices, questionable “unlocked” listings, swollen or worn batteries and phones that cannot run the apps you need.
What changed from the iPhone 6?
The industrial design remained recognizably the same, but almost every important internal component changed. The A9 system-on-chip replaced the iPhone 6’s A8, RAM doubled from 1GB to 2GB LPDDR4, and the storage subsystem became faster. The rear camera rose from 8MP to 12MP, the front camera from 1.2MP to 5MP, and video recording gained 4K at 30 frames per second. Live Photos, second-generation Touch ID, hands-free “Hey Siri,” improved LTE and Wi-Fi and the Rose Gold finish rounded out the update. Apple also moved to stronger 7000-series aluminum after the bending concerns associated with the earlier generation. The result was a phone that looked familiar but felt considerably faster and more capable (AnandTech specifications).
Specifications at a glance
| Specification | iPhone 6s | iPhone 6s Plus |
|---|---|---|
| Display | 4.7-inch, 1334×750 IPS LCD | 5.5-inch, 1920×1080 IPS LCD |
| Dimensions | 138.3×67.1×7.1mm | 158.2×77.9×7.3mm |
| Weight | 143g | 192g |
| Processor and memory | Apple A9; 2GB LPDDR4 RAM | |
| Rear camera | 12MP, no optical image stabilization | 12MP with optical image stabilization |
| Front camera | 5MP with Retina Flash | |
| Video | 4K at 30fps | |
| Storage at launch | 16GB, 64GB, 128GB | 16GB, 64GB, 128GB |
| US launch price | $649 / $749 / $849 | $749 / $849 / $949 |
Specifications and launch prices are from AnandTech’s original review (source).
#1 Best Overall
- 4.7-inch Retina HD display. 5G capable
- Advanced single-camera system with 12MP Wide camera; Smart HDR 4, Photographic Styles, Portrait mode, and 4K video up to 60 fps
- 7MP FaceTime HD camera with Smart HDR 4, Photographic Styles, Portrait mode, and 1080p video recording. Home button with Touch ID for secure authentication
- A15 Bionic chip for lightning-fast performance. Durable design and IP67 water resistance
- Up to 15 hours of video playback
Design, materials and ergonomics
Neither model introduced a new shape. Both retained the rounded aluminum body, curved edges, camera protrusion, bottom-mounted Lightning port, speaker, microphone and 3.5mm headphone jack of the iPhone 6 family. The 6s models were slightly thicker and heavier, partly because of the stronger enclosure and 3D Touch hardware. Rose Gold joined the existing finishes.
The 6s is the easier everyday phone: 143g, compact enough for many one-handed tasks and less intrusive in a pocket. The 6s Plus weighs 192g and its wider body makes one-handed use substantially harder. Its size is worthwhile if you read, watch video, navigate or type on a larger screen, but “Plus” did not automatically mean better ergonomics.
Performance: the upgrade you noticed every day
AnandTech described the A9 as the strongest smartphone system-on-chip it had tested at the time. Browser and system benchmarks put both phones clearly ahead of the iPhone 6 generation, while faster storage improved installs, launches and file operations (system performance testing). The move to 2GB of RAM was equally important: Safari tabs and recently used apps were less likely to reload, and iOS felt more responsive under multitasking.
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3D Touch and iOS 9
3D Touch used pressure sensors and a Taptic Engine to add a second interaction layer. Pressing a supported icon exposed Home-screen Quick Actions; pressing a link, message or email could show a “peek” preview, with a deeper press opening it. Pressing the keyboard enabled cursor control, and supported apps could expose shortcuts without navigating through menus.
For people who learned the gestures, this reduced repetitive tapping. The problem was discoverability: iOS rarely made it obvious which controls responded to pressure, so many owners never used the feature. AnandTech’s software analysis reached a useful middle position—3D Touch was technically impressive and genuinely efficient in supported workflows, but not universally essential (software review).
Live Photos, another launch feature, captured motion and sound around a still image. “Hey Siri” could work without the phone being connected to power. Both features were more immediately understandable than 3D Touch, although Live Photos and 4K video consumed storage quickly. Later iPhones replaced 3D Touch with Haptic Touch, making the 6s implementation historically notable but not a reason to buy one now.
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Rear camera
The 12MP rear camera produced more detail than the iPhone 6’s 8MP unit and added 4K recording at 30fps. Live Photos and the True Tone flash improved the shooting experience, while the 6s Plus added optical image stabilization. That stabilization helps reduce handshake in stills and video, especially in dim light; the smaller 6s lacks it.
Rank #2
- This phone is unlocked and compatible with any carrier of choice on GSM and CDMA networks (e.g. AT&T, T-Mobile, Sprint, Verizon, US Cellular, Cricket, Metro, Tracfone, Mint Mobile, etc.).
- Tested for battery health and guaranteed to have a minimum battery capacity of 80%.
- Successfully passed a full diagnostic test which ensures like-new functionality and removal of any prior-user personal information.
- The device does not come with headphones or a SIM card. It does include a generic (Mfi certified) charging cable.
- Inspected and guaranteed to have minimal cosmetic damage, which is not noticeable when the device is held at arm's length.
AnandTech found 4K recording unusually usable for its time, without some competitors’ severe recording restrictions, stabilization losses or overheating behavior. That is a launch-era assessment, not a 2026 comparison with computational-photography systems (review conclusion).
Front camera
The 5MP selfie camera was a major improvement over 1.2MP. Retina Flash briefly brightened the display to illuminate a face in low light. Selfies and video calls were much more usable than on the iPhone 6, although modern phones deliver better dynamic range, noise reduction and low-light processing.
Displays: familiar resolution, better interaction
The resolutions did not change from the previous generation: 1334×750 on the 4.7-inch 6s and 1920×1080 on the 5.5-inch 6s Plus. Many contemporary Android flagships were sharper, but both LCDs offered strong viewing angles, good brightness and generally accurate sRGB-oriented color. The Plus rendered at a higher internal resolution and scaled to its physical panel, according to AnandTech’s analysis (display testing).
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The meaningful display innovation was pressure sensitivity, not pixel density. The 6s Plus’s larger panel is better for documents, maps and video; the 6s is easier to handle.
Battery life and charging
Apple fitted the 6s with a smaller battery than the iPhone 6 because internal space was needed for new components. Improvements in the A9 platform’s efficiency helped offset some of that reduction in the original tests. The 6s Plus generally lasted longer, aided by its larger battery, although AnandTech observed possible throttling during extended testing that it associated with the higher-resolution display and sustained workload (battery testing).
Those 2015 results cannot predict a used phone’s endurance. A battery that is eight to eleven years old may have lost substantial capacity or may have been replaced with a low-quality part. Before buying, open Settings → Battery → Battery Health & Charging; if the label differs, search Settings for “Battery Health.” Check Maximum Capacity, peak-performance status, rapid percentage drops, heat, unexpected shutdowns and any display lifting that could indicate swelling.
iPhone 6s versus iPhone 6s Plus: which should you choose?
| Choose the 6s when you value | Choose the 6s Plus when you value |
|---|---|
| Lower weight and easier one-handed use | Longer battery endurance |
| A more pocketable body | A larger, sharper display |
| Lower cost in comparable condition | Optical image stabilization |
| Compact backup-phone duties | Video, reading, maps and travel use |
The Plus is not simply a bigger 6s. It is heavier, less comfortable for small hands and often more expensive in similar used condition. Pick it for its battery, screen and OIS—not because larger is automatically better.
Software support in 2026
The phones launched with iOS 9 and do not support iOS 16. Apple’s security-release index lists iOS 15.8.8 for all iPhone 6s models, released May 11, 2026 (Apple security releases). Apple’s iOS 16 documentation shows support beginning with the iPhone 8, iPhone 8 Plus and iPhone X (iOS 16 update history).
Rank #3
- Unlocked and Compatible with AT&T / Tmobile and all Service providers that Use AT&T / Tmobile Network. NOT Compatible with Verizon or any service provider that uses Verizon Network. Check before Purchase
- This device is Preowned, Tested and Passed in Excellent Condition, Battery Life Minimum 80% or more as compare to new.
- IOS Version upgradable to 15.8.5 but the device continues to receive security updates under the iOS 15 branch.
- Includes a new cable only. User manual and charger are not included. SIM card is provided by your wireless service provider and is not included with this device.
- 4.7" Retina HD display, 12MP camera and 4K video at 30 fps / 7MP FaceTime HD camera with Retina Flash Black
A security patch on the older branch is not the same as full current support. New features are unavailable, and app compatibility is increasingly constrained. Some apps still install; others require a newer iOS version. Check every essential app—banking, authentication, messaging, navigation and streaming—before purchase rather than assuming all apps work or none do.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Network and connectivity risks
LTE bands vary by model and region. In the United States, compatibility depends on the exact A-model number, the carrier’s current policy and whether the handset is genuinely unlocked. 3G shutdowns and carrier changes make VoLTE support especially important. Ask the seller for the model number and confirm it with the intended carrier before paying.
There is no 5G. Lightning remains the charging and data connector, while the 3.5mm headphone jack is still a practical advantage. NFC is present, but payment and identity features can be limited by the older software branch.
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Do not treat 16GB as a bargain. iOS occupies part of the capacity, and apps, cached media, Live Photos and 4K clips consume the remainder quickly. The 64GB model is the minimum sensible choice for most buyers; 128GB is preferable for photography, offline media or extended use. A clean 64GB phone with a healthy battery is more useful than a perfect-looking 16GB unit.
Buying a used iPhone 6s in 2026
Buy when
- You need an inexpensive secondary, emergency or music phone.
- The handset is 64GB or 128GB, unlocked and compatible with your network.
- Battery health is acceptable or a reputable replacement is documented.
- The seller provides a return period and the phone passes functional tests.
Avoid when
- You need current iOS features, demanding games or guaranteed long-term app support.
- The phone is 16GB, Activation Locked or advertised as unlocked without proof.
- The battery is swollen, shuts down unexpectedly or the display is lifting.
- There is no return policy or the device has an unknown repair history.
Pre-purchase checklist
- Confirm Activation Lock is removed and the phone reaches the normal setup screen.
- Open Settings → General → About and verify model number, storage, IMEI and carrier-lock information.
- Check Battery Health, maximum capacity and peak-performance status.
- Test Touch ID, both cameras, flash, microphones, speakers, vibration, GPS, Wi-Fi, Bluetooth and Lightning charging.
- Make a cellular call and test the proximity sensor with the phone at your ear.
- Inspect every part of the screen for dead zones, nonresponsive edges or an “Important Display Message.”
- Confirm the device can update to iOS 15.8.8 and that your essential apps support its installed iOS version.
- Keep the seller’s return window until all tests are complete.
Repair and accessory considerations
A battery replacement can make sense for an unlocked 64GB or 128GB phone you already own. Apple lists service options at Apple iPhone repair; independent parts and guides are available from iFixit, and Best Buy offers repair services through Geek Squad. Do the arithmetic first: a battery is difficult to justify if the phone is 16GB, damaged or unable to run required apps.
For charging, use a certified Lightning cable and a basic compatible charger. Apple’s accessory catalog is at Apple Lightning accessories; Anker and Belkin also sell compatible products (Anker, Belkin). Avoid expensive accessory bundles for a temporary backup device.
Bottom-line buying decision
The iPhone 6s was one of Apple’s best internal upgrades disguised as an unchanged design. In 2015, its A9 performance, 2GB RAM, cameras and 3D Touch made it a top-tier phone. In 2026, affordability and simplicity are its only strong arguments. Buy a well-checked 64GB or 128GB unlocked unit for basic or backup duties; choose a newer used iPhone if you need modern apps, better cameras, stronger network support or a longer software future.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
