Products / Documents and files
Hoq Reader
Your books in your drive, on an Xteink e-reader, with your place kept.
What it does
Hoq Reader is a library on the web plus firmware for Xteink X3, X4 and X4 Pro e-readers. Your books live as files in a folder you pick in your Hoq Storage drive, called Books unless you change it.
You install the firmware from Chrome or Edge on a computer over a USB-C cable. On the reader you open Settings, Hoq Reader, Link, then type the six digits shown on reader.hoq.app. The reader then downloads the books you send it and keeps your place in step with the web.
EPUB, plain text and Markdown go to the reader. Comics (CBZ, CBR, CB7) and PDF open in the browser only. Firmware updates come over the air from Hoq. The firmware is built on the open-source CrossPoint Reader.
In numbers
200 MBlargest book you can add
3Xteink models supported: X3, X4, X4 Pro
7file formats in the library: EPUB, TXT, Markdown, CBZ, CBR, CB7, PDF
33font families in the reading-look catalog
Specifications
| Readers supported | Xteink X3 and X4 (ESP32-C3) and X4 Pro (ESP32-S3). The X4 Classic is not supported yet. |
|---|---|
| Formats sent to the reader | EPUB, TXT and Markdown. |
| Formats read in the browser only | CBZ, CBR, CB7 comics and PDF. |
| Largest book | 200 MB per file. |
| Where books live | In a folder of your Hoq Storage drive, Books by default. |
| Installing | From Chrome or Edge on a computer over USB-C. The installer detects which reader you plugged in. Phones and Safari cannot reach USB devices. |
| Linking a reader | Type a six-digit code from the reader into reader.hoq.app. |
| Progress sync | Speaks the KOReader progress-sync protocol, so KOReader devices can sync to your library too. |
| Catalog for other apps | OPDS feed with All books, Continue reading and Unread lists, behind a per-device password. |
| Firmware updates | Over the air from Hoq's own release feed. |
Features
14 features, all shipped. Listed from the product's code and documentation; each row shows the day it was last checked.
| Books from your drive | Reads books from a folder you choose in your Hoq Storage drive. | |
| Upload a book | Adds a book up to 200 MB and makes a cover thumbnail from it. | |
| Shelves | Groups books onto shelves. | |
| Read in the browser | Opens EPUB, text and Markdown chapter by chapter, and comics and PDF page by page. |
| Send books | Delivers the books you send to a linked reader the next time it syncs. | |
| Reading progress | Keeps your place in each book in step between the reader and the web. | |
| Bookmarks | Keeps bookmarks made on the reader in your library. | |
| Lock screen pictures | Sets the picture each reader shows when it sleeps. | |
| Reading look | Picks the reader's font from the web. |
| Browser installer | Puts the firmware on the reader from Chrome or Edge over USB-C. | |
| Six-digit linking | Links a reader to your library with a code typed on reader.hoq.app. | |
| Over-the-air updates | Updates the reader's firmware from Hoq's release feed. |
| KOReader sync | Accepts reading progress from KOReader devices. | |
| OPDS catalog | Lists your books for any OPDS reading app. |
Works with
- Hoq StorageYour books are files in a folder of your Hoq Storage drive.
Your data
| Where it is kept | Book files stay in a folder of your own Hoq Storage drive. Your library, progress and bookmarks are kept by Hoq Reader. |
|---|---|
| Getting it out | The books are ordinary files in your drive, so you can download them from Hoq Storage. No export of progress or bookmarks is documented. |
| If you leave | Not documented on a public page yet. |
APIs and standards
- OPDS catalog at /opds (Basic auth with a device password)
- KOReader progress sync at /kosync
- Firmware release feed at /v1/firmware/latest
- Standard: EPUB
- Standard: OPDS
- Standard: KOReader sync protocol
- Standard: Web Serial
Compared
| Checked 2026-11-01 | Hoq Reader | CrossPoint Reader (stock) | calibre Content server |
|---|---|---|---|
| Price | Not published on reader.hoq.app | Free, MIT licence1 | Free and open source2 |
| E-readers supported | Xteink X3, X4, X4 Pro | Xteink X3, X4, X4Pro, X4Classic, Seeed reTerminal Sticky, M5PaperMono and others1 | not published3 |
| Formats on the device | EPUB, TXT, Markdown | EPUB, XTC/XTCH, TXT, BMP1 | not published3 |
| Where your books live | A folder in your Hoq Storage drive | On the reader's SD card; downloads from up to 8 saved OPDS servers1 | On your own computer running the server3 |
| Reading position sync | Built in, plus KOReader sync protocol | KOReader progress sync (you supply the server)1 | Remembers last position across devices while the server runs3 |
| Install | Browser installer over USB-C (Chrome or Edge) | Web flasher or esptool1 | Desktop app on Windows, macOS or Linux2 |
| Firmware updates | Over the air from Hoq | Over the air from GitHub releases1 | not applicable3 |