What are all the differences between the iPhone 4S and the iPhone 4? Which one is best for my needs?

With even a detailed look at both the iPhone 4S and either of the iPhone 4 models -- the iPhone 4 (GSM) or iPhone 4 (CDMA) -- one would be unlikely to notice major differences.

However, even though they may not have major differences visible to the naked eye -- there nevertheless are major differences between the iPhone 4 and the iPhone 4S.

Photo Credit: Apple, Inc.

External Differences

The iPhone 4S and iPhone 4 models all use the same general all stainless steel body design and a thin "metal band" that wraps around the sides of each phone. However, the iPhone 4S and iPhone 4 (GSM) have an access panel on the right side (and an enclosed Micro SIM card) and the iPhone 4 (CDMA) does not have an access panel or a SIM card.

Additionally, the iPhone 4 (GSM) has three antenna "breaks" in the metal band (one on the top and one on each side toward the bottom) and the iPhone 4 (CDMA) and iPhone 4S have four (two on both sides toward the top and bottom).

The rear camera also has considerably better specs on the iPhone 4S -- capable of shooting 8 megapixel stills and 1080p 30 FPS video. The iPhone 4 models, by contrast, are capable of shooting 5 megapixel still photos and 720p 30 FPS video. Both lines have a VGA quality front-facing camera designed for use with Apple's "FaceTime" software (although it works equally well with third-party applications like Skype). The camera in the iPhone 4S is faster, too, and is ready to take photos within a second of launch and additional photos within a half second.

Identification Differences

One simple way to externally identify the iPhone 4S and iPhone 4 models, as well as all other iPhone models, is by the model number printed in small type on the back of the phone.

The model number printed on the back of the GSM-equipped iPhone 4 is A1332, the model number on the back of the CDMA-equipped iPhone 4 is A1349, and the model number on the back of the iPhone 4S is A1387.

If the iPhone will boot, it may be even easier to lookup any of these models by order number with Everyi.com's Ultimate iLookup feature or the EveryMac app. Apple refers to the order number as "Model" in software. To find the "Model" select the "Settings" app and then click General > About > and scroll down until the field is visible.

Everyi.com's Ultimate iLookup and the EveryMac app also can identify these iPhone models by EMC number and the last four characters of their serial numbers.

Battery Life Differences

Battery life has changed a bit between the iPhone 4S and the previous iPhone 4 models. All of these models provide an Apple estimated 40 hours of audio playback, 10 hours of video playback and 6 hours of Internet use on 3G, but Apple has increased the official battery life estimates for the iPhone 4S to 8 hours of talk time on 3G (up from 7 hours on the iPhone 4 models) and reduced the official Internet use on wi-fi (9 hours down from 10 hours). Standby time also has been reduced from 300 hours to 200.

In "real world" testing, these differences are muted for most tasks, but the difference in battery life during 3D gaming use is the downside to the significantly improved performance of the iPhone 4S for graphics tasks.

Wireless Connectivity & Data Differences

A major point of differentiation is that the iPhone 4S is a dual-antenna equipped "world phone" that supports both GSM and CDMA networks -- UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz), and CDMA EV-DO Rev. A (800, 1900 MHz) -- and the "antenna automatically switches between send and receive." It supports 802.11b/g/n and Bluetooth 4.0, too. HSDPA is up to a theoretical maximum of 14.4 Mbps.

AnandTech has additional information about the iPhone 4S antenna capabilities that also may be of interest.

By contrast, the earlier iPhone 4 models support either GSM or CDMA networks, Bluetooth 2.1+EDR, and only support a maximum theoretical HSDPA download speed of 7.2 Mbps.

Unfortunately, it also is worth noting that Apple has disabled the CDMA capability on unlocked iPhone 4S models purchased in the United States.

Internal Differences

Internally, the iPhone 4S is considerably more powerful -- with a dual-core Apple A5 processor compared to a single core Apple A4 processor on the iPhone 4 models -- although the iPhone 4S and iPhone 4 both have 512 MB of RAM. Apple reports that the iPhone 4S is twice as fast overall and has seven times the graphics performance, and independent benchmarks and testing largely confirm this claim.

Capacity has been increased to 16 GB, 32 GB, and 64 GB for the iPhone 4S (16 GB for the current model), compared to 16 GB and 32 GB for the originally offered iPhone 4 models (and 8 GB for the current low-end models).

iOS Support & Software Differences

Both the iPhone 4 and iPhone 4S are capable of running iOS 5 (as well as iOS 6), but only the iPhone 4S is capable officially of running "Siri," Apple's recently acquired "intelligent assistant" software program that endeavors to parse naturally spoken questions and provide voice answers using the web as its source and perform basic software tasks as well (like adding an appointment to a calendar or preparing and sending a text message).

In the "real world," Siri doesn't always perform perfectly, but it still can be useful.

When running iOS 6, the iPhone 4S also supports Turn-by-Turn Navigation, Flyover, Panorama photographic mode as well as "Made for iPhone" hearing aids, whereas the iPhone 4 supports none of those features. It still doesn't support "Siri" either, although hacks exist.

Comparison Chart

These differences -- processor, storage, connectivity, battery life, software, cameras, and identifiers -- along with pricing information are summarized below for your convenience:

	iPhone 4 (GSM)	iPhone 4 (CDMA)	iPhone 4S
Processor:	Apple A4	Apple A4	Apple A5
Original Storage:	16, 32 GB	16, 32 GB	16, 32, 64 GB
Current Storage:	8 GB	8 GB	16 GB
GSM/EDGE:	Yes	No	Yes
UMTS:	Yes	No	Yes
HSDPA:	Yes (7.2 Mbps)	No	Yes (14.4 Mbps)
HSUPA:	Yes	No	Yes
EV-DO:	No	Yes	Yes
Bluetooth:	2.1+EDR	2.1+EDR	4.0
Talk Time (3G):	7 Hours	7 Hours	8 Hours
Talk Time (2G):	14 Hours	None	14 Hours
Battery (3G Web):	6 Hours	6 Hours	6 Hours
Battery (Wi-Fi):	10 Hours	10 Hours	9 Hours
Battery (Music):	40 Hours	40 Hours	40 Hours
Battery (Video):	10 Hours	10 Hours	10 Hours
Standby Time:	300 Hours	300 Hours	200 Hours
SIM Card:	Micro	None	Micro
Original iOS:	iOS 4.0	iOS 4.3	iOS 5
Maximum iOS:	iOS 6 (Partial)	iOS 6 (Partial)	iOS 6 (Complete)
Siri Support:	No (Hacks Only)	No (Hacks Only)	Yes
iOS 6 Read Offline:	Yes	Yes	Yes
iOS 6 Turn-By-Turn:	No	No	Yes
iOS 6 Flyover:	No	No	Yes
iOS 6 Panorama:	No	No	Yes
Still Camera:	5 Megapixels	5 Megapixels	8 Megapixels
Video Camera:	720p	720p	1080p
Model No:	A1332	A1349	A1387
Price* (Intro):	US$199 US$299	US$199 US$299	US$199 US$299 US$399
Price* (Current):	US$0	US$0	US$99

These prices all require, or required, a two-year contract in the US. Unlocked and contract free models are available at a premium.

So, which one is best for me?

Ultimately, as the vast majority of the cost of owning an iPhone is tied to the plan rather than the upfront cost of the device -- at least in countries where it is sold locked and subsidized -- it makes little sense to not purchase an iPhone 4S (or a newer iPhone 5) should you wish to purchase an iPhone.

The iPhone 4 is only marginally cheaper when the total cost of ownership over two years is considered, and those on tight budgets typically would be better off doing without a smartphone altogether than saving US$100 up front. However, those who find the faster performance, larger storage capacity, faster mobile data support, better camera, and additional software features of the iPhone 4S unnecessary still could be happy with an iPhone 4 and perhaps find a way to put the US$100 savings to better use.

Site sponsor PowerMax has used iPhones available for sale free of sales tax.

Also see:

• What are all the differences between the iPhone 4 (AT&T/GSM) and the iPhone 4 (Verizon/CDMA)?
• What are all the differences between the iPhone 4 and the iPhone 3GS?
• What are the main differences between every iPhone -- the iPhone 5, 4S, 4, 3GS, 3G and the original model? How can each iPhone be identified quickly?