Xteink X4 vs S4: Which Reader to Buy in 2026?

Earlier in 2026 the Xteink X4 became the first non-Kindle e-reader to crack Amazon’s e-reader top-10 — outselling the Kindle Colorsoft, according to the listing coverage that followed. A $69 button-only pocket reader did that. Then two more Xteink devices entered the rumor mill at once, and the question “xteink x4 vs s4” started showing up in every Reddit thread with no single guide to answer it.

This is that guide. It covers the X4 (shipping now), the rumored S4, and the rumored X4 V2 Pro — and it also answers the comparison more people actually search for: the X3 vs the X4. The short version is at the top; the long version — full specs, every decision factor, and the firmware ecosystem that makes these devices interesting — is below it.

Quick AnswerThe ProblemSpec TableWhat Each Device IsFirmwareWhich to BuyFAQ

Quick Answer

The two most common buying freezes in the community right now both come down to “buy now, or wait?”:

If you only want the smallest, simplest reader and don’t care about apps, there’s a fourth option this guide keeps in view: the older Xteink X3. It’s the most-searched comparison in the lineup (“xteink x3 vs x4”), and for a specific buyer it’s still the right call. More on that below.

The Problem: Too Many Xteinks, Not Enough Clarity

A year ago “which Xteink should I buy” had one answer, because there was one device people talked about. That is no longer true. There is now a shipping product (the X4), an older sibling that quietly stayed on sale (the X3), and two rumored devices (the S4 and the X4 V2 Pro) that dominate the threads despite the fact that nobody outside Xteink has held one.

That creates three traps for buyers:

The way out is to anchor the decision on what you actually read and where you read it — not on the most exciting unreleased spec sheet. That’s what the rest of this guide does, starting with the hardware as it’s currently understood.

Spec Table

Only the X4 (and the older X3) have shipped. The S4 and X4 V2 Pro columns are rumored/leaked — pieced together from official teaser materials, Joshua Lowcock’s tracker, Notebookcheck, Good e-Reader, and eReadersForum — and should be read as “what’s been claimed,” not “what’s confirmed.” Where research has no figure, the cell says so rather than guessing.

Two things worth flagging up front, because they trip people up:

• The X4 has no “storage” in the phone sense. Its ESP32-C3 carries 16MB of flash for the firmware; every book lives on the microSD card. Reviews that quote a “16GB” or “32GB” X4 are conflating the bundled card with onboard memory.
• The X3 charges over a magnetic pogo-pin cable, not USB-C. If you buy an X3, the cable is not interchangeable with your phone charger, and a wrong 2-pin pogo cable will charge but not carry data — which trips up anyone trying to flash it from a laptop.

What Each Device Is — and the X3 Question

Before comparing them, it helps to understand what each product is trying to do.

The Xteink X4 is a button-only pocket e-reader built on an ESP32-C3 chip. It has no touchscreen, no front light, and no app ecosystem. It runs DRM-free EPUB and TXT files only. Its entire appeal sits in three things: it is tiny (77g) and pocketable, it is inexpensive ($69), and its hardware is open enough that the community built CrossPoint and a constellation of firmware alternatives on top of it. If you want a focused reading device and you are comfortable with a modest amount of setup, it is a complete product. If you need Kindle, Libby, or a front light, it is the wrong product — full stop.

The Xteink X3 is the smaller, older sibling that never went away — and “xteink x3 vs x4” is the single most-searched comparison in the lineup. It has a smaller screen (which means a denser, higher-PPI image for crisp text in a tinier body), adds NFC for tap-to-open shortcuts, and runs the same XTEINK OS, so CrossPoint and X3-focused forks like INX work on it. The catch that surprises buyers: the X3 charges over a magnetic pogo-pin cable, not USB-C, so it’s one more proprietary cable to keep track of. The X3 is the right buy for one specific person — covered in the buyer scenarios below — and the X4 is the right buy for almost everyone else.

The Xteink S4 is, if the leaks hold, what happens when Xteink replaces the ESP32 stack with Android 11. The design philosophy would shift entirely: instead of flashing custom firmware to add capability, you’d sideload APKs; instead of buttons, a touchscreen; instead of no front light, adjustable warm-to-cool lighting. That would make the S4 the first Xteink device to compete directly with a Kindle or Kobo at the software layer. The tradeoff in the rumored build: Android 11 without Google Play Services (apps sideloaded, not from the Play Store), and no CrossPoint. None of this is confirmed — no S4 has shipped, and there are no verified specs.

The Xteink X4 V2 Pro is a third path that most mainstream coverage underplays. Surfaced via Joshua Lowcock’s tracker, the V2 Pro is rumored to add what X4 owners most requested — touchscreen and a front light with warm/cool settings — while keeping Xteink’s own OS rather than Android, and it may move from the ESP32-C3 to an Allwinner chip, which would open a Linux path. For owners who want the hardware upgrades without the Android pivot, it would be the natural successor. The problem: it is pre-production with no confirmed release date and no price. Specifics like exact thickness are not something any sourced material confirms, so treat any precise mm figure you see online as unverified.

Firmware: The Real Reason the X4 Matters

The single best argument for the X4 over a rumored device isn’t a spec — it’s that the X4 (and X3) sit on an open ESP32 platform that a real community has built on. None of this exists for the S4 or V2 Pro yet.

CrossPoint is the flagship: the main firmware for both X3 and X4, written in C, with roughly 5,200 GitHub stars and an active issue tracker. The current stable release is 1.3.0 (May 2026) — “145 changes from 53 contributors” — and since v1.3.0 it can take SD-card OTA updates without USB. It’s what most owners end up running, and it’s the firmware our setup guide walks through flashing.

Around it sits a genuine ecosystem of forks, each scratching a different itch:

• CrossInk (uxjulia/CrossInk, ~531 stars) — adds reading stats, a reading calendar, Bionic Reading, and improved fonts. The build string in the wild is CrossInk-ESP32-1.2.9.4-tiny. It’s also a common pick for locked-device owners.
• Microreader — written from scratch and X4-only (no X3 support, though users keep asking). If you’re on an X3, this one isn’t for you.
• Papyrix (bigbag/papyrix-reader) — lightweight, adds FB2 / Markdown / TXT plus theming and support for additional (right-to-left) scripts. Note it does not support OTA updates.
• AvesO3 — an AO3 fanfiction reader firmware built on CrossPoint 1.2.0, for unlocked devices only. Niche, but beloved by the fanfic crowd.

For position sync and library transfer there’s also KOReader Sync and the open-source CrossPoint Sync app (iOS + Android), which adds Wi-Fi book transfer and web-article clipping as a fourth transfer method beyond Calibre, web upload, and WebDAV.

There’s an official lane too: XT-Cloud, Xteink’s own cloud book-sync service (an XT-Cloud account plus the official Companion App handles wireless transfer for the X3 and X4). It has no public API, so it’s a convenience layer rather than something the community can build on — but it exists, and it’s the most hands-off way to get books onto the device.

None of this runs on the S4. If the S4 ships on Android, its analog of “community enhancement” would be KOReader’s Android build — excellent and well-maintained, but a different tool and a different community. The V2 Pro’s firmware story is simply unknown: if it keeps a flashable architecture it might host CrossPoint’s successor someday, but nothing exists for it yet. For a head-to-head of every option, see the firmware comparison.

One buying note: the firmware lockdown that blocked custom firmware on some units (reported around early May 2026) only affects devices bought from AliExpress, Taobao, and other Chinese domestic retailers. Units from xteink.com and Amazon are not affected, per Xteink’s own statement. If custom firmware matters, buy from xteink.com or Amazon and verify the USB flasher the moment the device arrives.

The Hardware Differences That Decide It

Front light

The X4 (and X3) have no front light; the rumored S4 and V2 Pro both add one with warm/cool adjustment. This is the single most-requested hardware feature in the X4 community, and the limitation that most consistently pushes long-term owners toward clip-on accessories or other devices. The workaround is real — Xteink sells its own magnetic reading light (about $10), and third-party clip lights and DIY setups exist — but a workaround is a workaround. If you read in bed or on planes regularly, an X4 needs an accessory; the S4 and V2 Pro would solve it at the hardware level.

One more X4-specific tip if you read outdoors: white X4 units can wash out in direct sun, and CrossPoint ships a setting called Sunlight Fading Fix (under Display settings) made for exactly that.

We do not yet have S4 or V2 Pro units. Front-light quality — whether warm/cool adjustment is smooth or notchy, and whether uniformity holds on a 4.3” panel — is the thing we most want to verify hands-on.

Touchscreen vs. physical buttons

The X4 uses three navigation rockers plus a power button; no touch. The rumored S4 and V2 Pro both add touchscreens. The community is genuinely split here. Critics are right that the X4’s buttons behave differently in menus versus books with no on-screen reminder, accidental presses happen, and menu navigation has a learning curve (stock firmware makes it worse; CrossPoint makes it much better). Defenders are equally right that physical buttons mean no accidental touch events while reading — your thumb rests on a rocker and pages turn only when you press. If you’re coming from any touchscreen device you’ll find the buttons slower at first; give it a week on CrossPoint and the friction mostly disappears. If you want it to just work on day one, a touchscreen device will feel more intuitive.

DRM, apps, and the Kindle migration question

This is the clearest dealbreaker. The X4 runs DRM-free EPUB and TXT only. It cannot run the Kindle app, connect to Libby/Overdrive, or touch Kindle Unlimited. The rumored S4, on Android 11, would change that via sideloaded APKs: Amazon distributes the Kindle APK from its own site (no Play Store needed), Kobo and Libby’s Android apps can be sideloaded, and KOReader’s Android build covers EPUB/PDF/MOBI/CBZ/FB2 and more — at the cost of manual, per-app installation.

If your library is locked in Kindle’s ecosystem, there’s a grey area worth naming carefully: CrossPoint (like KOReader) cannot open DRM-protected EPUB. The legal, non-piracy approach is to read DRM-free books you already own or buy DRM-free from the start (Project Gutenberg, Standard Ebooks, many indie stores), and — for books you’ve purchased — to de-DRM your own library before converting. We don’t publish a step-by-step for that, and we don’t endorse stripping DRM from books you don’t own; the safe default if Kindle is non-negotiable is to wait for the S4. A practical gut check: do you mostly read books you bought from Amazon or borrowed from a library? If yes, the X4 only makes sense if you’re willing to move to DRM-free sources.

Battery and power

The X4’s battery is fine for most people — owners charge it roughly once a week. The rumored S4 is said to carry a larger battery, but Android draws more continuously than the X4’s bare-metal ESP32 firmware (background sync, OS processes), so don’t assume the read-time ratio matches the capacity ratio. The S4’s real battery number needs hands-on data that doesn’t exist yet.

Which Device for Which Buyer

The “xteink x4 vs s4” question rarely has one universal answer — it depends entirely on what and how you read. Find yourself in the grid, then read the note below it.

On the X3 charge-cable trap. If you go X3 and ever plan to flash it from a laptop, get the 4-pin pogo cable — the 2-pin version charges but carries no data, and a lot of “my X3 is locked” panic is really just a charge-only cable.

On reading more and scrolling less — the quietest but most common reason people buy an Xteink. A button-only device with no browser, apps, or notifications is a behavioral tool: tiny friction to open anything but a book, always in your pocket, far fewer dopamine traps than the phone it replaces. One owner wrote it “saved 8 hours and 40 minutes of doomscrolling by… READING! This is the first book I’ve finished in years.” Another credited “finishing 10 books in 2 weeks” after short chapters “got me out of my reading slump.” A third: “I feel extremely manipulated by my iPhone and the access to social media.” The counterintuitive part: if breaking the phone habit is your goal, the X4’s “limitation” is the feature, and the S4’s app store is the wrong direction — a device that can sideload apps can run the same traps you’re escaping. It’s a habit-support nudge, not a cure, but the simplest device is the most effective one.

Practical Application: Picking and Setting Up Your Device

If you’ve read this far and you’re still deciding, here’s the decision boiled down to a short procedure. Answer in order; stop at the first “yes.”

How to choose:

1. Do you need Kindle, Kobo, or Libby? If yes, wait for the S4 (and accept there’s no confirmed date). If no, continue.
2. Do you need a built-in front light you can’t solve with a clip-on? If yes, your only in-ecosystem option is the rumored V2 Pro — an open-ended wait. Otherwise continue and buy now.
3. Do you want the smallest possible body and NFC, and are you fine with a proprietary charge cable? If yes, buy the X3. If no, continue.
4. Otherwise, buy the X4. It’s the default for almost everyone: shipping today, $69, the largest firmware community.

If you land on the X4 (or X3), the first-hour setup is short:

Steps:

1. Buy from xteink.com or Amazon, not AliExpress/Taobao — that’s the only way to be sure the unit isn’t firmware-locked.
2. When it arrives, plug it into a laptop and confirm the USB flasher detects it before you do anything else. (On an X3, make sure you’re using the 4-pin data pogo cable, not a 2-pin charge-only one.)
3. Flash CrossPoint — our CrossPoint flash guide walks through it step by step.
4. Format a microSD card as FAT32 (exFAT only if it’s a card larger than 32GB) and load a few DRM-free EPUBs to test before committing your whole library.
5. If you read outdoors on a white unit, turn on Sunlight Fading Fix under Display settings.

Before you trust it with your reading life, load 3–5 EPUBs from different sources (Project Gutenberg, Standard Ebooks, a Calibre export) and confirm each opens and remembers your place after a reboot. That one check catches most format and SD-card problems on day one.

Frequently Asked Questions

These are the real questions circulating across r/XTEINK, r/xteinkereader, and r/ereader right now, with direct answers.

Conclusion: The Honest Answer

Before the bottom line, keep one thing in view: almost everything exciting about the S4 and V2 Pro is still unknown. No units have shipped, so their specs, prices, dates, battery life, E-Ink refresh quality, KOReader behavior, and firmware openness are all unconfirmed. That’s the whole reason this decision is hard — and the whole reason it’s simpler than it looks.

The “xteink x4 vs s4” debate collapses to a few lines once you stop treating rumored devices as if they’re for sale:

• Buy the X4 now if you read DRM-free files (or you’re trying to read more and scroll less). It ships, it’s $69, and it has by far the biggest firmware community.
• Wait for the S4 only if Kindle, Kobo, or Libby is non-negotiable — and accept there’s no confirmed ship date.
• Get the X3 if you want the smallest body and NFC over a bigger screen; track the V2 Pro only if you need a front light without leaving the XTEINK firmware world.

The X4’s advantages are known in practice today; the S4’s and V2 Pro’s are still promises on paper. If you decide on the X4, two reads will get you the rest of the way: the firmware comparison to choose between CrossPoint and its forks, and the CrossPoint flash guide to set it up in your first hour. Grab the X4 from xteink.com, flash CrossPoint, and start reading — you can always reassess when the S4 actually exists.

Independent — not affiliated with Xteink.

Sources

• Official Xteink S4 teaser
• Xteink S4 price announcement
• Official Xteink Note blog (S4 announcement)
• Joshua Lowcock S4 tracker
• Joshua Lowcock X4 V2 Pro tracker
• Notebookcheck S4 coverage
• Good e-Reader S4 coverage
• eReadersForum S4 Android pivot analysis
• The Well-Appointed Desk S4 vs Boox Palma analysis
• eReadersForum X4 long-term use thread
• eReadersForum X4 limitations review
• eReadersForum firmware lockdown thread
• Liliputing firmware lock coverage
• The eBook Reader blog firmware lock coverage
• CrossPoint Reader firmware

Last updated: June 19, 2026. This page will be updated when S4 units ship and first reviews appear.