# eSIM vs iSIM: What Is the Difference?

> iSIM moves the SIM into the phone’s main processor rather than a chip beside it. What that changes for manufacturers, and why it changes nothing for you.

Phones and networks · Published 2023-06-21 · Updated 2026-08-21 · 3 min read

Page: https://esimradar.com/blog/esim-vs-isim

![A macro photograph of microchips soldered onto a circuit board.](https://esimradar.com/blog-images/esim-vs-isim/hero-36169774-1280.webp)

*The difference is one of these chips: an eSIM is its own component, an iSIM is a room inside the processor.*

Both remove the plastic card. An eSIM is a dedicated secure chip soldered to the phone’s board; an iSIM moves that same secure element inside the main processor, so there is no separate component at all.

For anyone buying a travel plan, that is the entire difference, and it is not one you will ever notice. iSIM uses the same profiles, the same QR codes and the same providers as eSIM. If a phone is advertised as iSIM, everything on this site applies to it unchanged.

## What iSIM changes

It is a standard rather than a marketing word: ETSI defines the integrated version in [TS 103 666-2, the Integrated Smart Secure Platform specification](https://www.etsi.org/deliver/etsi_ts/103600_103699/10366602/17.01.00_60/ts_10366602v170100p.pdf). The gains are real too, they are just the manufacturer’s rather than yours:

- Space. Removing a discrete chip frees board area — which matters enormously in a watch or a tracker, and barely at all in a phone.
- Power. Fewer components and shorter traces mean marginally lower idle draw.
- Cost. One fewer part to buy, place and solder, across millions of units.
- Security, arguably. Integrating the secure element into the processor removes a physical bus between them that could in principle be probed.

## What it does not change

Everything a traveller touches is defined by [GSMA SGP.22, the remote SIM provisioning specification for consumer devices](https://www.gsma.com/solutions-and-impact/technologies/esim/wp-content/uploads/2024/09/SGP.22-v2.6.pdf) either way:

- The profile format and the provisioning exchange. [Downloading a SIM works identically](https://esimradar.com/blog/esim-explained).
- [QR codes](https://esimradar.com/blog/esim-qr-code) and [manual SM-DP+ entry](https://esimradar.com/blog/enter-esim-qr-code-manually).
- Storing several profiles and keeping one or two active.
- Which providers work, and which plans are worth buying.

> **Note:** There is no such thing as an "iSIM plan" to look for. Any travel eSIM installs on an iSIM device exactly as it would on an eSIM one, and a provider advertising iSIM compatibility as a feature is describing the specification, not something they built.

## Where you will meet iSIM first

Not in a flagship phone. The devices where saving a few square millimetres justifies the integration work are smartwatches, industrial sensors, vehicle modems and asset trackers — categories where the SIM is a meaningful fraction of the whole board. The GSMA wrote them their own provisioning specification, [SGP.32, the eSIM IoT technical specification](https://www.gsma.com/solutions-and-impact/technologies/esim/wp-content/uploads/2024/04/SGP.32-v1.1.0.pdf), for exactly the constrained devices where an integrated SIM makes most sense.

Some phone chipsets now support it, and adoption will be gradual and unannounced. It is not a feature to wait for or to pay extra for.

## The question worth asking instead

Whether the phone supports eSIM at all, which [takes ten seconds to check](https://esimradar.com/blog/esim-phones) and determines whether any of this is available to you. After that, the only variable left is the plan: [price per GB](https://esimradar.com/faq) by [destination](https://esimradar.com/country).

## Common questions

### Is iSIM better than eSIM?

Better for the manufacturer — less space, less cost, marginally less power. For the user the two behave identically, so there is nothing to choose between them.

### Do travel eSIMs work on an iSIM phone?

Yes, without any difference. The profile format and provisioning are the same specification, so any travel plan installs exactly as it would on an eSIM device.

### How do I know whether my phone has eSIM or iSIM?

You generally cannot from the interface, and it does not matter. Dial \*#06# — if an EID appears, the phone can download profiles, whichever way the hardware is built.

### Should I wait for an iSIM phone?

No. It brings no user-facing benefit, and adoption is happening quietly inside chipsets rather than as a headline feature.

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