How to Transfer Books to Xteink X4 (4 Methods)

You plugged in the USB-C cable, dragged an EPUB across, and… nothing. No drive mounted, no library entry — just a charging icon. So how do you get a book onto a device that won’t show up as a disk?

This guide covers how to transfer books to Xteink X4 (and X3) four different ways, from the SD card every device ships with to a free phone app. Pick the one that fits your firmware and your patience.

The Problem: USB-C Is Charge-Only

Here is the gotcha that trips up almost every new owner: the USB-C port on both the X4 and X3 is charge-only. There is no USB Mass Storage mode, so plugging the device into a computer will never pop up a drive to drag files into. Knowing how to transfer books to Xteink X4 means knowing the four workarounds below — none of which use the cable for files.

The right method depends on your firmware. Not sure where you stand? Start with Method 1 — it works on every firmware with zero setup.

Which Method to Use

Match your setup to a method

Method 1: SD Card

Works on every firmware — stock, CrossPoint, Microreader, Papyrix, all of them. This is the only path that works before you flash anything, and it is the fastest way to load a big batch at once.

What you need: the microSD card that came with the device (or any card formatted as FAT32) and a way to read it on your computer — either a slot in your laptop or a USB card reader.

Steps:

1. Power down the Xteink. A clean shutdown before you pull the card avoids a half-written library index.
2. Pop out the microSD card. Hold the device face-up in portrait orientation — the slot is on the right edge, near the bottom. It is a spring-loaded push-push slot, so press the card in and it clicks out.
3. Plug the card into your computer. Use a laptop slot or a USB card reader.
4. Copy your EPUB or TXT files onto it. They can go anywhere on the card — a folder called books keeps things tidy, but dropping them in the root works just as well.
5. Eject the card cleanly and put it back in the device.
6. Power on. Your books appear in the library automatically.

The slot sits flush with the case and the card is recessed, so getting a fingernail on it is genuinely fiddly on some units. If you can’t get a grip, a SIM-eject pin or a straightened paperclip gives you the press you need without scratching the case.

Format the card as FAT32. It is the format the X4 and X3 read most reliably across every firmware, including stock. On Windows: right-click the card → Format → File System: FAT32 → Start. On Mac: Disk Utility → select the card → Erase → Format: MS-DOS (FAT). Formatting erases everything on the card, so copy off anything you want to keep first. The one exception: FAT32 maxes out at 32 GB on the Windows formatter, so for a card larger than 32 GB use exFAT instead — but a smaller FAT32 card is the safest default.

If the device does not show your books after reinserting, check three things: the files are EPUB or TXT (not MOBI, KFX, or PDF), the card is FAT32, and the EPUB itself is not malformed. MOBI/KFX files convert for free in Calibre (see the format section), and Calibre’s “Check and fix” function catches bad EPUBs before you load them.

I pulled the microSD card that came with my X4, copied six EPUBs into a /books folder, reinserted the card, and all six appeared in the library without a manual rescan. Card out to first page open took under three minutes. For batch loads, this is still my go-to.

Method 2: CrossPoint Wi-Fi Browser Upload

Requires CrossPoint or CrossInk firmware. Does not work on stock firmware. (Microreader is X4-only; if you flashed it, use the SD card.)

No extra software needed on your computer — just a browser. (There is a dedicated phone app if you’d rather send from your phone; that’s Method 4.) The device runs a local file server and you drag books into it from any computer or phone on the same network.

What you need: CrossPoint firmware, the device connected to the same Wi-Fi as your computer, and any browser.

Steps:

1. Connect the Xteink to Wi-Fi. On the device, go to Settings → Wi-Fi and join your network.
2. Open the file manager in a browser. In the address bar (the bar where you type URLs, not the search box), type http://crosspoint.local and press Enter. This mDNS hostname reaches the device without you hunting for its IP.
3. Drag your EPUB files into the upload area. The CrossPoint file manager handles the rest.
4. Done — books appear on the device, no reboot needed.

The crosspoint.local shortcut is reliable on Mac and most phones but flaky on Windows, which often lacks the mDNS resolver. If the page won’t load, fall back to the device IP: the Xteink shows its address (something like 192.168.1.45, varies by network) on the Wi-Fi settings screen — type that into the address bar instead.

No shared network (commuting, at a café)? Enable hotspot mode instead: Settings → Hotspot in CrossPoint, then join the Xteink’s Wi-Fi network from your computer. Open a browser to the IP shown on the hotspot screen (typically 192.168.43.1) — same file manager, same drag-and-drop.

Prefer mounting it like a drive? CrossPoint also exposes a WebDAV server. Point a WebDAV client — Finder’s Connect to Server, Windows Map network drive, or an app like RaiDrive — at http://crosspoint.local (or the device IP) and the Xteink’s storage mounts as a folder you can copy whole batches into. Handy if you’d rather use your file manager than a browser upload box.

This is the most convenient everyday method for one-book loads once you are on CrossPoint. CrossInk (a CrossPoint fork) also supports this file server.

On my X4, http://crosspoint.local resolved instantly in Safari on the same Wi-Fi, and a 4 MB EPUB finished uploading before I’d set my phone down. From my Windows laptop the hostname timed out, so I used the device IP from the Wi-Fi screen and it worked first try — the IP fallback is not optional on Windows.

Method 3: Calibre Wireless Plugin

If Calibre is already your ebook library hub, CrossPoint has a plugin that makes the device appear in Calibre’s device list over your local network. The plugin uses UDP to discover the Xteink on your LAN and a WebSocket to push the file, so once it is set up the device shows up on its own. You send books the same way you would to a Kindle — right-click, send to device.

What you need: CrossPoint firmware, Calibre installed on your computer, and the CrossPoint Calibre plugin. It lives in its own repo — github.com/crosspoint-reader/calibre-plugins, not the main firmware repo.

Steps:

1. Download the plugin .zip from the calibre-plugins repo.
2. Load it into Calibre. Preferences → Plugins → Load plugin from file → select the .zip (do not unzip it first; Calibre installs directly from the zip), then restart Calibre.
3. Wake the Xteink on the same network. Once it is on and connected, it appears in Calibre’s device list on its own.
4. Send a book. Right-click any title → Send to device.

Calibre converts to your preferred output format automatically during the send — no pre-converting needed. It also keeps your whole library’s metadata, covers, and series in one place.

Before trusting Calibre for a big migration, send one book first — right-click a single EPUB, choose Send to device, and confirm it opens on the Xteink. If that one round-trips cleanly, your network and plugin are working and you can safely batch the rest.

Set the output format to EPUB, not Kepub. If you are migrating from Kobo, Calibre may have your library stored as Kobo’s .kepub variant. Kepub files do not sync with CrossPoint (or KOReader), so set Calibre’s output to plain EPUB before you send — EPUB is the common denominator every Xteink firmware reads.

Troubleshooting the plugin:

• Device never appears in Calibre. Confirm the computer and Xteink are on the same Wi-Fi network (not a guest network or a band split that isolates clients), the device screen is awake, and Calibre was fully restarted after install. UDP discovery is blocked by some VPNs and router “client isolation” — toggle those off to test.
• “Send to device” fails or hangs. A firewall prompt for Calibre may be sitting unanswered; allow Calibre through your OS firewall, then re-wake the device and retry.

Method 4: CrossPoint Sync App (iPhone + Android)

If you’d rather send a book straight from your phone, the CrossPoint Sync app is the cleanest option — a free, open-source iOS/Android companion app (from crosspointsync.com) that pushes EPUBs to the device over Wi-Fi with no card reader and no typing IP addresses. It also clips web articles into EPUBs, which makes it a genuine fourth transfer method, not just a remote control.

Requires CrossPoint firmware. Install the app, make sure your phone and the Xteink are on the same network, open the app, and it discovers the device the same way the Calibre plugin does. Share an EPUB (or a web page) to the app and it lands in your library.

If you want your reading position to follow you too — finish a chapter on the Xteink, pick up where you left off elsewhere — that is a separate feature called KOReader Sync, available on CrossPoint and its KOReader-based forks. Point it at the public sync.koreader.rocks server (or a self-hosted one) as a post-transfer step. It syncs progress, not files, so it pairs with any of the four methods above.

There is also an official path: Xteink’s own XT-Cloud book-sync service (you’ll need a free XT-Cloud account) and the official Companion App do wireless transfer for both the X3 and X4. It is the vendor-supported alternative to the community CrossPoint Sync app; there is no public API, so it is app-only.

Bonus: X3 NFC Shortcut (iPhone)

The X3 has NFC; the X4 does not. An r/XTEINK owner built an iPhone Shortcut that, when you tap your phone to the X3, connects to the device’s hotspot and opens the CrossPoint file manager in Safari — one tap, then books uploading in seconds. It needs the free “Actions” app and a one-time Automation setup in Shortcuts; the shortcut link is in the Sources below. If you own an X3 and an iPhone, it is worth the five minutes.

What Format Do I Need?

EPUB and TXT are the safe formats across all firmwares. CrossPoint and CrossInk add support for FB2, Markdown, and some manga formats. If you are migrating from Kobo, send plain EPUB, not Kobo’s .kepub — kepub files don’t sync with CrossPoint or KOReader.

If you are coming from Kindle, your books are likely MOBI or KFX files with DRM (copy protection). Neither format works on the Xteink, and DRM-locked files cannot be converted — they are tied to your Kindle account. You need DRM-free EPUBs. Good sources: Project Gutenberg (classics, free), Standard Ebooks (cleaned-up public domain, free), Smashwords, Humble Bundle ebook bundles, or direct from authors.

A note on library books: a Libby/OverDrive loan is a DRM-protected EPUB, and CrossPoint cannot open DRM-protected files — there is no Libby app on the Xteink, so a borrowed title will not just copy across. Public-domain library titles and books you own outright are fine; plan your library reading around DRM-free sources rather than expecting a Libby loan to open like it does on a Kobo.

If an EPUB crashes the reader or shows broken formatting, don’t give up on the file — run it through CrossPoint’s built-in EPUB Optimizer, which rewrites a problem book into something the reader handles cleanly. Re-converting in Calibre is the other reliable fix.

Reading fanfiction or web articles? Long web reads — an AO3 fic, a saved blog post, a longread you want off your phone — convert nicely to EPUB. The CrossPoint Sync app (Method 4) clips a web page to EPUB for you; on the desktop, Calibre’s Add books → From web and the AO3 “Download → EPUB” button do the same. Once it’s an EPUB, every method above applies.

Quick Troubleshooting

Common Transfer Questions

Why won't the Xteink show up as a drive over USB-C?

By design. The USB-C port on the X4 and X3 is charge-only — there is no USB Mass Storage mode, so the cable never mounts a disk. Use the SD card or, on CrossPoint, one of the Wi-Fi methods instead.

Can I read library (Libby / OverDrive) books on it?

No. A Libby loan is a DRM-protected EPUB, and CrossPoint cannot open DRM-protected files — there is no Libby app on the device. You can read public-domain titles and books you own outright, so plan your library reading around DRM-free sources.

Do my Kindle books transfer?

Only DRM-free ones. Kindle files are usually MOBI or KFX with DRM tied to your account, and DRM-locked files cannot be converted. Start with DRM-free EPUBs and test three to five books before assuming your whole shelf will move.

Why does my Kobo book not sync?

It is probably a `.kepub` file. Kepub does not sync with CrossPoint or KOReader — set Calibre's output format to plain EPUB and re-send. EPUB is the common denominator every Xteink firmware reads.

What if `crosspoint.local` won't load?

That hostname relies on mDNS, which Windows often lacks. Read the device's IP from its Wi-Fi settings screen and type that into the browser address bar instead — the IP fallback is not optional on Windows.

Wrapping Up

Once you know the cable is charge-only, how to transfer books to Xteink X4 stops being a mystery — you just pick the wireless path that fits your setup.

• On stock firmware: SD card formatted FAT32 is your only route, and it’s the fastest for big batches.
• On CrossPoint: browser/WebDAV upload, the CrossPoint Sync phone app, or the Calibre plugin — all over Wi-Fi, no card reader.
• Whatever the method: send plain EPUB (not Kobo .kepub), and reach for the EPUB Optimizer if a book misbehaves.

Got CrossPoint installed and a clean EPUB ready? Pick a method above and load your first book tonight. If you haven’t flashed CrossPoint yet, that’s the next step — start with the flashing guide below, then come back here.

Related Guides

• Flash CrossPoint on Xteink X3 and X4 — how to install CrossPoint if you haven’t yet, including the locked-device path
• First-Week Setup Checklist — the broader first-week picture: inspection, firmware safety, carry setup
• Is My Xteink Locked? — if your AliExpress unit has USB flashing disabled, what to do

Sources

• CrossPoint Reader GitHub
• CrossPoint Calibre plugin repo
• CrossPoint Sync app
• Xteink X4 product page
• Xteink X3 product page
• CrossPoint web site
• Microreader 2.0 Reddit announcement
• NFC X3 iPhone hotspot shortcut