The Firmware Directory
Every Xteink X3 & X4 firmware, plugin, and flashing method — in one place
Stock firmware is the weak link on the Xteink X3 and X4; the community fixed it. Every replacement here is checked against primary sources, repo by repo, version by version, with a full install guide one click away.
Verified August 11, 2026. Not affiliated with Xteink. Flashing custom firmware can void your warranty.
Start here: which firmware?
Find the sentence that sounds like you. When in doubt: CrossPoint. Prefer to be asked? The 30-second chooser narrows all twelve to one pick, locked-device safe.
“I just want the best all-round reader”
Our pick
TL;DR
CrossPoint Reader
The main community firmware: best-supported, runs on both the X3 and X4, flashes from the browser, and reverts cleanly.
“I want reading stats + nicer typography”
TL;DR
CrossInk
A CrossPoint fork that adds reading statistics and Bionic Reading, and fixes the missing Unicode glyphs stock renders as diamonds.
“My books are FB2, Markdown, or HTML”
TL;DR
Papyrix
Reads FB2, Markdown, and HTML on top of EPUB, and one binary auto-detects X3 vs X4. Higher risk: no OTA.
“I read Chinese, Japanese, or Korean”
TL;DR
CrossPoint CJK / KO
Localized CrossPoint forks with real CJK font rendering and native menus. The KO build also runs on the X3.
“I live on AO3 fanfiction”
TL;DR
AvesO3
An AO3-styled library that checks for and downloads new chapters right on the device. X4 only, and still experimental.
“I want the simplest possible EPUB reader”
TL;DR
Microreader
Deliberately minimal: drop EPUBs anywhere on the SD card and read. X4 only, and you should be comfortable with PlatformIO.
“I want offline apps, a dictionary & plugins”
TL;DR
SUMI
Offline-first (no WiFi) with ~20 built-in apps, a StarDict dictionary, and a Lua plugin framework. X3 + X4.
Got the new X4 Pro?
Beta firmwareThe X4 Pro (launched July 21, 2026) ships factory-unlocked under Xteink's firmware guarantee on store units, so the locked-device brief below mainly matters for the X3 and the base X4. But custom firmware is still catching up to the Pro's new hardware.
- CrossPoint: beta only. It is not in the stable build yet. As of v1.5.0 (Aug 7, 2026) the release notes say the X4 Pro "isn't supported in this build yet — a beta is up on the site for testers." Flash the tester build only if you can live with rough edges.
- No USB-C. The Pro charges over a pogo-pin adapter, not USB-C, and adds a touchscreen, front light and real-time clock the beta is not proven against. Treat flashing it as experimental until a stable port lands.
Weighing the upgrade first? Read X4 Pro vs X4: upgrade, stick, or skip?
The full directory
Sorted safest to riskiest, so the rows you can trust with a first flash come first; within a risk level, our picks and full X3+X4 support break ties. Risk is judged for a non-technical owner.
✓ supported · ~ partial/unverified · ✕ not supported. One Bluetooth heads-up: every custom firmware drops it to save RAM except Stock, CrumBLE, SUMI and CrossPoint BLE.
| Firmware | Type | X3 | X4 | Bluetooth | Version | Risk | Best for |
|---|---|---|---|---|---|---|---|
| Stock Xteink | Factory default | ✓ | ✓ | ✓ | — | None | Out-of-box simple reader (what you start on) |
| CrossPoint Reader | Main pick | ✓ | ✓ | ✕ | v1.5.0 | Medium | The default: best all-round reader |
| CrossInk | CrossPoint-based fork | ✓ | ✓ | ✕ | v1.5.0 | Medium | Reading stats, Bionic Reading, glyph fixes |
| CrossPoint KO | Language pack | ✓ | ✓ | ✕ | v1.3.0-ko | Medium | Korean reading + UI (also runs on X3) |
| Midad by Foulad | Language pack | ✓ | ✓ | ✕ | v1.8.57 | Medium | Arabic / Persian / Kurdish: RTL UI + Quran (X3 + X4) |
| SUMI | CrossPoint-based fork | ~ | ✓ | ✓ | v0.6.3 | Medium | Offline apps, dictionary, Lua plugins, emulator |
| CrossPoint CJK | Language pack | ✕ | ✓ | ✕ | v0.3.4 | Medium | Chinese / Japanese reading + UI |
| Microreader | Minimal reader | ✕ | ✓ | ✕ | 2.0-dev | Medium | Minimal, distraction-free EPUB-only |
| CrossPet | CrossPoint-based fork | ✓ | ✓ | ✕ | v1.8.4 | Medium | Vietnamese UI + gamified virtual pet & games |
| InkPoint X | CrossPoint-based fork | ✓ | ✓ | ✕ | v2.2.12 | Medium | All-in-one X3/X4 reader: stats, dictionary, font downloads, OTA |
| CrossMux | CrossPoint-based fork | ✓ | ✓ | ✕ | v1.5.5 | Medium | Apps hub + WeChat Reading; Chinese build |
| WitchHunt Reader | CrossPoint-based fork | ✓ | ✓ | ✕ | v2.21 | Medium | Clock + Markdown; the renamed CrossPoint++ |
| CrossPoint BLE | CrossPoint-based fork | ✓ | ✓ | ✓ | v1.3.1 | Medium | Bluetooth page-turner remotes |
| Microreader+ | Minimal reader | ✓ | ✓ | ✕ | main | Medium | Minimal EPUB; adds X3 + SD flashing |
| inx | CrossPoint-based fork | ✕ | ✓ | ✕ | v1.0.19 | Medium | Clean reader: annotations + image rendering |
| CrumBLE | CrossPoint-based fork | ~ | ✓ | ✓ | v4.7.3 | Medium | BLE page-turner remote + collections |
| CPR-vCodex | CrossPoint-based fork | ~ | ✓ | ✕ | v1.5.0.9 | Medium | Reading habits: stats, streaks, dictionary, flashcards |
| CrossPoint JP | Language pack | ✓ | ✕ | ✕ | v0.1.16 | Medium | Japanese: furigana + vertical writing (X3) |
| SEEK Reader | CrossPoint-based fork | ✕ | ✓ | ✕ | v1.0.7 | Medium | Quick-settings reader + dictionary (X4) |
| aalu | CrossPoint-based fork | ✕ | ✓ | ✕ | v3.0.0 | Medium | Auto series grouping (X4, build-it-yourself) |
| CrossPoint Flow | CrossPoint-based fork | ✕ | ✓ | ✕ | v3.0.1 | Medium | Lua plugins + iPod-style UI, CJK |
| DX34 | CrossPoint-based fork | ✕ | ✓ | ✕ | v0.0.5 | Medium | Richer EPUB controls (X4 / DX34) |
| Papyrix | CrossPoint-based fork | ✓ | ✓ | ✕ | v1.27.0 | High | FB2 / Markdown / HTML, multi-script |
| AvesO3 | Niche / specialized | ~ | ✓ | ✕ | v1.3.1 | High | AO3 fanfiction workflow |
| Rustmix | Standalone (not a fork) | ✕ | ✓ | ✕ | v1.1.0 | High | Hindi / Devanagari reading (X4, advanced) |
The seven major firmwares open full guides on this site; every other row links to its repo or to the relevant section below.
Localization forks
Reading in Chinese, Japanese, or Korean? These CrossPoint forks add the fonts and menus that the main build lacks. Pick by language and model.
CrossPoint CJK · v0.3.4 · X4
Chinese and Japanese reading + UI, with external CJK fonts and typography fixes. Ships Simplified and Traditional builds. repo
CrossPoint KO · v1.3.0-ko.1 · X3 + X4
Korean UI with full Hangul/Hanja rendering. Unlike the CJK build (X4-only), it also runs on the X3, and it ships a complete standalone image set with SD-card update + WiFi OTA. Actively maintained. repo
Midad by Foulad · v1.8.57 · X3 + X4 · MIT
An Arabic-first CrossPoint fork: a fully mirrored right-to-left Arabic UI, correct Arabic/Persian/Ottoman-Turkish/Kurdish letter shaping, and a bundled Quran in Uthmani script with ayah/surah markers. The Arabic reading face (Tajawal) is built in; Noto Naskh and three dozen more families download over WiFi. Adds the Midad-app OPDS library with QR sign-in and cross-device page sync, reading stats, and OTA updates. One firmware auto-adapts to both the X3 and X4. Unlocked units only — it is not one of the two firmwares the OTA Unlocker serves. repo
CrossPoint JP · v0.1.16 · X3
A Japanese-focused CrossPoint fork (crosspoint-reader v1.2.0 plus the CJK fork’s improvements): furigana (ruby), vertical writing, downloadable JP fonts, and on-device Aozora Bunko search. Confirmed working on the Xteink X3 only; the X4 is unconfirmed, and there is no warranty. A separate, newer fork (mtskf/crosspoint-reader-jp) localizes the UI to Japanese on both models but adds no furigana or vertical text. repo
How to flash
Five methods, one default: start with the web flasher. If it can’t see your Xteink, you’re probably on a locked unit. Read the locked-device brief before trying anything else.
Web flasher
Chrome or Edge over USB, nothing to install. The default path for unlocked devices.
Full guideSD card
No PC required. Rescues a locked X3 directly from stock.
Full guideOTA Unlocker
Installs over WiFi. The recommended first step for a locked X4.
Full guideesptool
The command-line route, for Python users and custom builds.
Full guidePlatformIO
Build and flash from source. Required for contributing.
Full guideBefore you flash: the locked-device safety brief
Since April 2026, some Xteink units ship with USB flashing disabled. Two minutes here is the difference between a smooth flash and a stranded reader.
Is my device locked?
You can’t tell from the box. The only sure test is to connect over USB and try to flash. xteink.com and Amazon units are reported unlocked; AliExpress imports are the ones that have shipped locked. The new X4 Pro ships factory-unlocked by guarantee on store units.
If it is locked
X3: SD-card method (rename build to update.bin, hold left button + power) or OTA Unlocker. X4: OTA Unlocker only — the X3 SD button combo does not engage from X4 stock (it won’t brick, it just won’t fire). Only CrossPoint and CrossInk are supported on locked units.
The brick risk is real
Flashing unsupported firmware on a locked device can leave no recovery path. One owner soft-bricked a locked X4 flashing Shortbread over SD — afterwards even CrossPoint’s SD-recovery no longer engaged. Keep a known-good firmware.bin on the SD card, and on a locked unit flash only CrossPoint or CrossInk.
Software lock or hardware fuse?
Unconfirmed. Working workarounds suggest a software layer, not a permanent eFuse. Assume some risk regardless.
Golden rules
- Back up the full flash first (on unlocked units).
- Use a USB-C data cable, and wake the device before connecting.
- On a locked unit, flash only CrossPoint or CrossInk.
- Never write esptool to
0x0for CrossPoint and its forks; use0x10000. (Microreader's full image is the one exception; follow each repo's README.)
Still shopping? Read the buying advice in full: locked vs unlocked: buy the right unit.
"I have this problem" → the fix
Skip the spec comparison. Find your complaint on the left; the right column names the firmware that fixes it.
| The problem | What fixes it | Firmware |
|---|---|---|
| Stock firmware feels basic / clunky | Flash CrossPoint. It is the whole reason this scene exists. | CrossPoint |
| Missing Unicode characters show as diamonds | CrossInk added synthetic-glyph fallback rendering (PR #104). | CrossInk |
| My books are FB2 / Markdown / HTML | Papyrix reads all three natively; no converting. | Papyrix |
| I read Chinese / Japanese / Korean | Use the CJK or KO localization forks (KO also runs on the X3). | CJK / KO |
| I read mainly in Arabic, Persian, or Kurdish | Midad by Foulad is an Arabic-first CrossPoint fork: a mirrored RTL Arabic UI, correct letter shaping, and a bundled Quran. Unlocked units only — on a locked device use CrossPoint, which added Arabic/Farsi/Urdu RTL in v1.5.0. | Midad |
| I want reading stats and Bionic Reading | CrossInk tracks sessions and pages/min, and adds Bionic mode. | CrossInk |
| I want reading streaks, an on-device dictionary & flashcards, close to CrossPoint | CPR-vCodex layers analytics, streaks, achievements, an SD-card StarDict dictionary, and flashcards onto the CrossPoint base. | CPR-vCodex |
| Buttons should toggle bold / font size / dark mode | CrossPoint and its forks add button remapping and reader quick settings (bold, Bionic, dark mode). | CrossPoint forks |
| Keeping new AO3 chapters in sync is a chore | AvesO3 checks for and downloads new chapters on the device itself. | AvesO3 |
| I just want to dump EPUBs and read | Microreader scans the whole SD card. No folders, no fuss. | Microreader |
| I want offline apps, a dictionary, or real plugins | SUMI is offline-first with ~20 apps, a dictionary, and a Lua plugin framework. | SUMI |
| I want a Bluetooth page-turner remote | CrumBLE (a CrossInk fork) adds BLE remote support and collections. | CrumBLE |
| My device shipped USB-locked and won’t flash | X3: SD-card method (from stock) or the OTA Unlocker. X4: the OTA Unlocker, then its in-app SD update. Stick to CrossPoint/CrossInk. | See safety |
| I just got the new X4 Pro | It ships factory-unlocked, but CrossPoint support is beta-only (v1.5.0) and the Pro has no USB-C (pogo-pin charging). Flash the tester build only if you can tolerate rough edges. | X4 Pro note |
Troubleshoot the X3 & X4
Don't see your exact issue? The firmware FAQ has 51 fact-checked, cited answers: the SD-card error, bootloops, locked devices, recovery, Bluetooth, fonts. Search it by problem.
Plugins & customization
Custom fonts, themes, sleep-screen wallpapers, and SUMI's Lua plugin system: everything that runs on the device itself.
Browse pluginsSoftware & tools
Calibre, KOReader sync, OPDS servers, and book converters: the desktop and self-hosted side, and it works with any firmware.
Browse tools