hardware · which device

Which reader to put ExplorInk on

Four readers run our firmware, and they are not three versions of one thing. Pick by the day out, not by the spec sheet.

528×792 · 257 ppi

X4 Pro

480×800 · ppi open

480×800 · 218 ppi

LilyGo T5 S3 Pro

960×540 · 234 ppi

Bodies drawn to relative scale on one canvas, from panel sizes off our own devices. The X3 is the smallest and the sharpest of the four; the LilyGo board is the biggest and has no case around it. The X4 Pro is drawn at the X4’s panel size, because its own diagonal is not a figure we hold.

Pick by what you do

day hike, sightseeing, pocket carry

Xteink X3

smallestsharpestdaylight only

Smallest of the four, and the sharpest panel per inch.
No frontlight. When the light goes, so does the map.
Smallest area as well, and that is where city label density is worst.
Runs, not called supported: an off-screen pin’s distance label still lands on the scale bar.

riding, and after dusk

Xteink X4 Pro

frontlighttouch172 kB heap

Warm and cool frontlight on sliders, and the only cool channel of the four.
Three times the free memory of the C3 readers, measured.
Our reference device: new work is written on it first.

night walk, trek, group out of coverage

LilyGo T5 S3 Pro

own GNSSLoRadev board

Knows where it is with no phone. Nothing else here does.
Group positions travel over LoRa, no coverage in the chain. Everyone needs this board.
A bare board: no case, two readable buttons, and our build is an alpha.

only if you already own one

Xteink X4

discontinuedUSB-Cdaylight only

Takes the same build as the X3, no flag and no second install.
Discontinued August 2026. Ours left the desk ten days later.
So no current build has been run on one by us.

The frontlight is the fork that matters. Every way of using this we modelled has a night or a dawn in it, walking and riding both. Without one you have a daylight device, and nothing on the other side of the table buys that back.

Side by side

A green tick marks a cell that is a reason to pick that device. Every cell also says what it rests on: measured off that unit on our desk, vendor off the maker’s page or mail, open if nobody has established it. Panel pixels are framebuffers we pulled off these devices; the diagonals and the densities under them are vendor figures.

	X3	X4 Pro	X4	LilyGo T5 S3 Pro
Panel	3.7″, 528×792	480×800, diagonal not established	4.3″, 480×800	4.7″, 960×540
Pixel density	about 257 ppi	open	about 218 ppi	about 234 ppi
Grey levels	open	open	4, measured	16, vendor
Frontlight	none	warm and cool	none	warm only
Touch	none	GT911, plus a home key	none	GT911
Buttons	physical only, positions not measured	page turn each side, home key	four	two programmable inputs
Chip	ESP32-C3	ESP32-S3, 8 MB PSRAM	ESP32-C3	ESP32-S3, 8 MB PSRAM
Free heap, map and Bluetooth up	51.2 kB, measured	172 kB, measured	58.5 kB, measured	open
Fast refresh	open	488 ms, measured	500 ms, measured	open
Map render, one frame	1,257 ms, measured	1,183 ms, measured	open	open
Onboard GNSS	no	no	no	yes, a u-blox MIA-M10Q or a Quectel L76K
Long range radio	no	no	no	SX1262 LoRa, 433, 868, 915 or 920 MHz
Port	pogo pins, carrying data	pogo pins, dongle in the box	USB-C	USB-C
Runtime, map open	open	open	about 25 h from the battery slope, measured before August 2026	16.4 h frontlight off, 11.1 h at 40 %, measured
Build	explorink-v0.2.2, shared with the X4	explorink-x4pro-v0.2.2	explorink-v0.2.2, shared with the X3	explorink-t5s3pro-v0.2.2, alpha
Where it stands	runs, not called supported	supported, reference device	discontinued, none on our desk	development board, alpha

What nobody has measured

Weather. No IP rating on any of the four, and none tested wet or dropped.
Cold. Operating temperature open for every panel here. Winter riding is below zero.
Runtime on the Xteink line. Open on the X3 and the X4 Pro. The X4’s 25 hours is not theirs.
Frontlight quality. Two devices have one. Never compared side by side.
Sun on the panel. A refresh in daylight can come back white. Observed on the X4, not measured.

Before you buy

We quote no prices, because the only Xteink ones we hold come off a blog. Buy direct from xteink.com: the X4 Classic product page carries a written guarantee that units bought direct are exempt from third-party firmware restrictions, and it says that covers past and present models. Marketplace units are often the locked Chinese version, which never enumerates over USB, so the browser flasher cannot help with one. The install page points at CrossPoint’s unlock tool for that case, untried by us. The LilyGo board sells from lilygo.cc with and without the receiver, so pick the one with it.

Install it Files per device, the backup step first, and a flasher that runs in the browser. The hardware underneath One binary for two readers, and what a third target actually bills.