diff --git a/CHANGELOG.md b/CHANGELOG.md
index 168bd34f..704f1058 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@
## Added
+- Web UI
+ - Compress the embedded assets (minify + gzip) and switch to a single-page layout. #315
+
## Changed
## Fixed
diff --git a/Dockerfile b/Dockerfile
index 6ed31e03..e4b393a4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,6 @@ RUN apt-get update && apt-get install -y \
xxd \
python3 \
libjson-c-dev \
- golang-go \
git \
&& rm -rf /var/lib/apt/lists/*
diff --git a/Makefile b/Makefile
index 5e1d1df6..6f369d78 100644
--- a/Makefile
+++ b/Makefile
@@ -87,10 +87,20 @@ SRCS += \
OBJS = ${SRCS:%.c=$(BUILDDIR)/%.rel}
DEPS := ${SRCS:%.c=$(BUILDDIR)/%.d}
-HTML := $(shell find html -name '*.js' -or -name '*.html' -or -name '*.svg')
+HTML := $(shell find html -name '*.js' -or -name '*.html' -or -name '*.svg' -or -name '*.css' -or -name '*.ico')
-html_data.c html_data.h &: $(HTML) | tools
- tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -b BANK1 -d html -p html_data
+# Minified copy of the web UI sources, used as the fileadder input.
+# The raw html/ sources stay untouched for development; the minified
+# copy is a build artifact under output/.
+HTML_MIN := output/html_min
+.PHONY: html_min
+html_min: $(HTML)
+ rm -rf $(HTML_MIN)
+ mkdir -p $(HTML_MIN)
+ @for f in $(HTML); do python3 tools/minify.py $$f $(HTML_MIN)/$$(basename $$f) || exit 1; done
+
+html_data.c html_data.h &: $(HTML) | tools html_min
+ tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -b BANK1 -z -d $(HTML_MIN) -p html_data
$(VERSION_HEADER):
@printf '%s\n' "#ifndef VERSION_H" "#define VERSION_H" \
@@ -132,7 +142,7 @@ $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin: $(BUILDDIR)/rtlplayground.i
tools/output/imagebuilder -i $^ $@
tools/output/fileadder -a $(DEFAULT_CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
tools/output/fileadder -a $(CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
- tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -d html -p html_data -b BANK1 $@
+ tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -z -d $(HTML_MIN) -p html_data -b BANK1 $@
tools/output/crc_calculator -u $@
ln -sf $(MACHINE)/rtlplayground-$(FILENAME_EXTENSION).bin output/rtlplayground.bin
diff --git a/doc/webui-compression.md b/doc/webui-compression.md
new file mode 100644
index 00000000..775498b0
--- /dev/null
+++ b/doc/webui-compression.md
@@ -0,0 +1,106 @@
+# Compressing the Web UI Assets
+
+The Web UI (all files under `html/`) is embedded into the flash image and
+served over HTTP. Two build-time steps keep it small: a safe minifier and
+gzip compression of the embedded files.
+
+## How it works
+
+```
+html/ --(minify.py)--> output/html_min/ --(fileadder -z)--> flash image
+```
+
+- `tools/minify.py` removes comments (``, `//`, `/* */`) and
+ line-leading whitespace without touching string or regex literals, so
+ the output is functionally identical to the input. Binary files
+ (`.ico`) are copied through unchanged. The raw sources in `html/` stay
+ untouched for development; the minified copy in `output/` is a pure
+ build artifact. Comments and indentation are pure overhead for the
+ served bytes, so minification alone already reduces the transfer size
+ from 109,814 to 97,730 bytes, independent of gzip.
+- The Web UI is a single-page application: `index.html` holds all pages
+ as sections (`#/ports`, `#/vlan`, ...) that the sidebar switches
+ between via the URL hash. `login.html` stays separate because it is
+ the authentication gate. Only these two pages plus `main.js`,
+ `style.css`, the three SVG port images and the favicon are embedded.
+- All JavaScript (i18n, shared helpers, navigation and the per-section
+ scripts) lives in one `html/main.js` bundle that the pages load as
+ their only script, so the browser fetches it once and gzip can
+ compress across all of it. A section's initialisation runs when the
+ section is shown, its polling intervals run only while it is visible,
+ and re-entering a section refetches the data.
+- `fileadder -z` gzip-compresses every file (zlib, gzip format,
+ `Z_BEST_COMPRESSION`) when it generates the file table
+ (`html_data.c`/`html_data.h`) and when it embeds the files into the
+ final image. Both invocations run on `output/html_min/`, so the table
+ and the image always agree.
+- The httpd serves each file with `Content-Encoding: gzip` according to
+ the `gzip` flag in its `f_data` entry. The 8051 only copies compressed
+ bytes from flash to the socket; decompression happens in the browser.
+- Only the static files are compressed. The JSON API responses
+ (`/information.json`, `/vlanlist`, ...) are generated on the fly and
+ stay uncompressed.
+
+## Measured effect
+
+Build on any machine (the Web UI is machine-independent):
+
+| | bytes |
+|---|---:|
+| raw sources | 109,814 |
+| minified (comments and indentation removed) | 97,730 |
+| gzip (flash + wire) | 25,302 (23.0 %) |
+
+The minified assets are also what the browser receives when gzip support
+is missing or disabled, so the transfer size drops in both stages:
+109,814 → 97,730 bytes from minification, then → 25,302 bytes from gzip.
+
+The embedded data block ends at `0x5b977` without compression and at
+`0x462d6` with it, freeing ~86 KB of the 512 KB image.
+
+The consolidation helps at every step. The 17 scripts gzip to 23,302
+bytes as separate files but to 17,231 bytes as one `main.js` bundle,
+because the gzip dictionary spans all of them. The single-page layout
+then removes the per-page HTML and, more importantly, the repeated
+downloads: with the multi-page UI the browser fetched `main.js` on every
+navigation; the SPA fetches everything once and section switches are
+pure in-page JavaScript (measured on a real device: cold load ~450 ms,
+section switch ~60-160 ms, the only network traffic afterwards is the
+JSON polling of the visible section).
+
+## Notes
+
+- The files stay well below the `uint16_t` size limit of the file table
+ (largest gzip output: 17.2 KB for the merged `main.js`).
+- `fileadder` terminates the embedded files with a NUL directly after the
+ content (previously at `data_read + 1`), so the `strlen()`-based size
+ computation no longer depends on uninitialised buffer content.
+- `version.h` is now written by a single atomic `printf` (change from
+ upstream) instead of five separate `echo`s, so a parallel build
+ (`make -j`) can no longer read a half-written copy. It stays in
+ `.PHONY` so it is regenerated on every build.
+
+## Verification
+
+Decompress what the firmware embeds and compare it with the minified
+sources:
+
+```python
+import gzip, re
+h = open('html_data.h').read(); c = open('html_data.c').read()
+starts = dict((k, int(v, 16)) for k, v in
+ re.findall(r'#define FDATA_START_(\w+) 0x([0-9a-f]+)', h))
+sizes = dict((k, int(v)) for k, v in
+ re.findall(r'#define FDATA_SIZE_(\w+) (\d+)', h))
+entries = [(p, sizes[z], starts[s]) for p, s, z in
+ re.findall(r'\{"/([^"]+)", FDATA_START_(\w+), '
+ r'FDATA_SIZE_(\w+), \w+, 1\}', c)]
+d = open('output/rtlplayground.bin', 'rb').read()
+for name, size, start in entries:
+ assert gzip.decompress(d[start:start+size]) == \
+ open('output/html_min/' + name, 'rb').read()
+```
+
+`tools/httpd_sim` serves the raw files from `html/` and does not exercise
+the gzip path; a browser session against a flashed switch (or `curl
+--compressed`) is the final check.
diff --git a/html/bandwidth.html b/html/bandwidth.html
deleted file mode 100644
index 9b6b96f8..00000000
--- a/html/bandwidth.html
+++ /dev/null
@@ -1,21 +0,0 @@
-
-
-
-
-
- Ingress and Egress Bandwidth
-
-
-
-