Lector Xteink Firmware

Local only — nothing uploaded Firmware guide Est. 2026 · Lector

Screen

Format

Fit

Rendering

Dither style

Auto-contrast

Invert (neg.)

Files must match your screen within 1 px or the device rejects them, so pick the size that matches your reader. On device: set Sleep Screen = Custom and Wallpaper Format to match, then drop the files in /sleep.

Drop images here or click to choose

PNG · JPG · WebP · GIF · BMP · PXC — pick as many as you like. Drop an existing .pxc to re-target it to the other screen.

How it works & the auto settings

PXC is the device's packed format: a 4-byte little-endian width,height header then 2 bits/pixel (4 gray levels: black · dark · light · white), MSB-first. BMP output is a standard 2-bit, 4-gray bitmap the reader also accepts.

Auto rendering — the tonal range is measured. Photographs get dithering; logos / line art / text get crisp thresholding. Click the dither / threshold badge under any result to flip that one image; changing the Rendering dropdown resets them all.
Dithering — the panel's four levels sit 85 greys apart, so one mis-fired pixel is a whole step away from its neighbours, not a subtle speckle. Diffusion is Floyd–Steinberg, which passes on the whole error and so holds tone exactly; that is why photographs are usually dithered this way. Two things stop it gritting flat areas: the scan alternates direction row by row, which breaks up the diagonal streaks a one-way pass leaves, and a flat area lying close to one of the four levels is placed on that level with its error dropped, so no residue can pile up there. Gradients and detail still dither normally, and a tone genuinely between two levels still mixes both.
Cleaner — wallpapers converted before the above will still carry that grit. The Cleaner tab repairs finished .pxc and .bmp files in place of re-converting them, so nothing is re-scaled or re-toned. For a whole card, use scripts/clean_pxc.py from the repository.
Auto-contrast — stretches tones to use all four levels so flat images don't come out muddy.
Fit — Cover fills and crops; Fit letterboxes; Stretch distorts to fill.
Invert — only if a wallpaper shows up looking like a photo negative on your panel.
Re-target — drop a .pxc straight in; switch Screen to re-fit and re-encode for the other reader (the badge then reads e.g. X3 → X4).
Names — a downloaded .pxc is named for the reader it was fitted to, e.g. sunset_X3.pxc. Re-target it and the name follows the new screen.

All conversion is local (HTML canvas). No server, no upload.

Already converted a wallpaper and it came out with stray pixels scattered over a flat background? Drop it here. The cleaner reads a finished .pxc or .bmp, fills in the specks that error diffusion left in flat areas, and writes the file back at the same size and format. Nothing is re-scaled and no tone is re-mapped, so the image is otherwise untouched. Detail is kept: a speck is a tiny island of pixels enclosed by one single other level, so a line is safe however thin it is, and cleaning the same file twice changes nothing.

Drop converted files here or click to choose

.pxc and .bmp — up to about 100 at a time in the browser. For a whole SD card, use scripts/clean_pxc.py from the repository instead.

Keep a USB cable handy. Lector is a personal fork with one maintainer, so a build can still carry a bug. If one misbehaves, you can always re-flash from this page. Your books live on the SD card and are never touched. Update keeps your settings; a full install erases them.

Lector

Lector firmware for your Xteink X3 / X4, re-based onto the upstream CrossPoint reader with a thin layer of reading niceties on top. The build on this site is …. Use Update my reader if your reader already runs Lector, the full install further down if it does not, and the SD card download if it cannot be flashed over USB.

Current build on this site

…

Update writes only the app and resets the boot selector. Your books, settings, and Wi-Fi are kept — nothing is erased. Your reader must already be running Lector. Takes about 30–60 seconds.
New device? If your reader does not have Lector yet, use the full install below instead — Update alone will not work on a stock device.

What lector 0.27.0 does

New

Share Wi-Fi and OPDS logins with another reader. Settings, System, Share WiFi and OPDS sends them over the Nearby radio, so a second reader does not have to be typed in by hand. The other reader receives it from File Transfer, Nearby Reader. Both ask first: the bundle carries the passwords in the clear over a radio that is not encrypted, and both readers delete it straight after.
Pages to Paragraph, a new status bar item. Shows >P.0 on most pages, meaning the paragraph you are in ends before the next one starts. >P.2 means it runs two more pages.
Never is back as a Refresh Frequency. It turns off the page-counted refresh only. The panel is still cleaned when enough ink has moved to need it, so a long session does not end up smeared.

Fixed

Font downloads finish. A font file arrives over TLS from a server that sends 16 KB records, and the reader ran a few kilobytes short of the memory that needs, every time. It now borrows the framebuffer for the length of the transfer. The progress bar holds still while a file is in flight; that is the price of the file arriving at all.
A download that was making progress no longer gives up. A transfer stopping part way used to spend its attempts and quit while it was still moving forward, and a partial was thrown away whenever the server answered a resumed request with the whole file.
OPDS says when the server refused the login, instead of "Failed to fetch feed", which reads as a connection problem and sends you looking in the wrong place. The catalog that ships with the reader has no password set, so it needs yours.

Changed

The Caret selection style lost its underline and sits beside the row's first line, so a row that wraps is marked where reading starts. Brackets are finer.
The status bar's progress bar reaches the edge of the screen instead of stopping short of the bezel.

Reports version lector 0.27.0 on device. Earlier releases are on the releases page.

No USB, or a reader that will not take a flash? Download the app image and put it on the SD card, then on the reader open Settings, System, Firmware from SD card and pick the file. Any filename works.
This needs a reader already running Lector: the SD picker is part of Lector itself. It cannot install onto a stock reader, and it cannot revive one that does not boot — those need the full install below, over USB.

Download firmware.bin for the SD card

Install on a new device — or full rescue

Use this if your reader does not have Lector yet (fresh from the shop, still on the stock firmware), or if a device is dead, blank, or bricked. It writes the bootloader, partition table, and app from scratch — everything a reader needs to run Lector.

Warning: a full flash erases everything on the device. On a brand-new reader there is nothing of yours to lose. On a reader you have used, its books and settings stored in flash are erased. Book files on the SD card are not touched.

Use Chrome or Edge on a computer — you are already here (Web Serial only).
Plug the reader into a USB port with a data cable.
Click Update my reader (already running Lector) or Full install / rescue flash (a new or dead device), and pick the reader's serial port when asked.
Wait for the flash to finish, then reboot the reader by hand: press Reset, then Power. The X3 / X4 do not auto-reboot over USB.

Nothing is uploaded to a server. The firmware is served from this site and written to the device entirely inside your browser via esptool-js (the same engine the official ESP tools use).

How this works

Your Lector reader runs on an ESP32-C3 chip. This talks to the chip over the USB serial port using the browser's Web Serial API.

Update writes boot_app0.bin (OTA data, 0xe000) and firmware.bin (app, 0x10000) without erasing — so NVS settings and the book storage survive. This is the normal, data-preserving update.
Full install / rescue erases the chip, then writes the bootloader (0x0), partition table (0x8000), OTA data (0xe000), and app (0x10000). This is what a device without Lector needs — a stock reader has a different partition table, so an app-only Update would not boot.
One firmware serves both X3 and X4; the running code detects the model at boot.

Wallpapers,hand-picked.

Lector

Install on a new device — or full rescue

Wallpapers,
hand-picked.