GRLife does three things: it builds custom firmware, provides film library files and makes shutdown screens. All three happen in your browser; the site does not connect to the camera or write to the SD card, and you copy the files and carry out each step on the camera yourself. Below, three parts explain what each step does and where its limits are.
You import the official firmware; the custom firmware is built on your device
Custom firmware starts from the official BIN you get from Ricoh. Your browser first checks the model and version on your device, and only GR III 2.10 / 2.20 / 2.21, GR IIIx 1.60 / 1.70 / 1.71 and GR IV 1.20 / 1.21 (Beta) go further; it then combines the features you chose into a new firmware file, still on your device. GRLife does not distribute Ricoh firmware, and neither the official BIN nor the result is uploaded.
Features are combined as you choose, and checked before building
The page checks that the chosen features can go into one firmware file together; if the version or the combination does not fit, nothing is built. Before building you also confirm that you saved the official BIN, made a backup and read the supported scope, and you read and agree to the disclaimer and terms of use.
You flash it yourself, and can flash the official firmware back at any time
You copy the file to the root of the SD card and flash it with the camera’s own firmware update; to restore, you flash the official firmware you kept the same way. Flashing unofficial firmware carries risk: the camera may fail to start, data may be lost and the warranty will very likely be void, so back up first.
The custom firmware has been verified on every GR III body (Standard / Street / Diary / HDF) and every GR IIIx body (Standard / Urban Edition / HDF). The GR IV is offered as a Beta: verified on the Standard body; the HDF shares the same official firmware. The Monochrome is not supported yet.
A film library file is bound to one camera
Once custom firmware with GRLife Pro is flashed, the camera’s Info page shows an 8-character device code. The film library makes FILMS.GRF for that code, and the file works only on that camera; with a file issued for another camera, the films show in grey with a padlock.
Downloading sends only the device code and the chosen films to the site, to make the file and count downloads; no account is needed and no photos are involved.
Once loaded, films work without the card
The camera reads the film library from the GRLIFE folder on the SD card and loads the film you pick into a slot on the Film library screen. Loaded films are kept in the camera and work without this card afterwards.
The built-in films come from gr3-film-mods, fitted with spektrafilm and used under CC BY-SA 4.0. The other groups are style imitations fitted to community LUTs, not manufacturer data.
Shutdown screens are handled by GRLife Pro too: the site turns photos into files and the camera’s menu switches them.
At power off, GRLife Pro has the camera read another picture
The Ricoh GR’s shutdown screen is a 720×480 JPEG inside the firmware. At power off the camera picks this picture according to the body version and hands it to the decoder to show. GRLife Pro steps in where the decoder receives the file path: if you picked your own picture on the Shutdown screen page, it swaps in the path of the copy stored in the camera; otherwise it lets the path through unchanged.
The factory shutdown images and their settings are never rewritten, so Factory screen switches back at once, and flashing back the Ricoh factory firmware brings the factory screen back too. This happens only for the shutdown screen; other pictures such as the start-up screen and keyboard backgrounds are not affected.
Copied into the camera when chosen, used only after a check
The camera lists BYE1.JPG to BYE9.JPG from the SD card on the Shutdown screen page. When you choose one, GRLife Pro checks that it is a 720×480 baseline JPEG within 128 KB, copies it into the camera’s internal storage, reads it back block by block, and marks it as in use only when every block matches.
This file in the camera has a fixed length and is rewritten whole each time; if copying or the check fails, it is not used and the shutdown screen stays as it was. So the shutdown screen still shows after you remove, swap or format the SD card.
The site encodes photos into JPEGs the camera reads
Photos are cropped to 720×480 in your browser and encoded with libjpeg-turbo as baseline JPEGs with 4:2:0 chroma subsampling and the same quantization tables as the factory shutdown image (standard quality 90); a very detailed photo that goes over 128 KB gets a lower quality until it fits. Before packing, the site checks each file against the same rules the camera uses.
None of this needs the official firmware, and your photos are not uploaded. The download starts with an SD folder laid out like your SD card, plus a readme.
The old debug-script method is retired
GRLife used to rewrite the shutdown image inside the camera with its factory debug scripts, which needed the official firmware, several runs from the card and readback checks. Now that GRLife Pro switches it in the menu, that process is retired; the GR IV, which does not support GRLife Pro, currently has no shutdown screen tool.
On a camera whose shutdown image was changed the old way, Factory screen shows that replaced image; new shutdown screens are not affected, and flashing back the Ricoh factory firmware restores Ricoh’s own image.
Files stay on your device; you act on the camera
All three parts process files in your browser: the official firmware, the generated firmware and your photos are never uploaded. The site does not connect to the camera or write to the SD card; you copy the files and act on the camera yourself.