diff --git a/utils/analyze_log.py b/utils/analyze_log.py
new file mode 100644
index 0000000..c52ae0f
--- /dev/null
+++ b/utils/analyze_log.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python3
+"""Offline analysis of a log/forecast pair produced by the BrewPi server.
+
+Usage:
+    python analyze_log.py <date_time> <sud_name> [--log-dir <dir>]
+
+Example:
+    python analyze_log.py 20260628T184903 Sud-0010
+
+Loads logs/<date_time>_{sud_name}.json (log and forecast) and renders the same
+two plots the PyQt GUI shows: the 3-panel realtime strip chart and the
+forecast-vs-actual comparison.
+"""
+
+import argparse
+import json
+import sys
+from pathlib import Path
+
+import matplotlib
+matplotlib.use("TkAgg")
+import matplotlib.pyplot as plt
+from matplotlib.ticker import AutoMinorLocator
+
+
+def _style_axis(ax):
+    ax.set_facecolor('white')
+    ax.spines['top'].set_visible(False)
+    ax.spines['right'].set_visible(False)
+    ax.xaxis.set_minor_locator(AutoMinorLocator())
+    ax.yaxis.set_minor_locator(AutoMinorLocator())
+    ax.tick_params(which='major', direction='out', labelsize='small')
+    ax.tick_params(which='minor', direction='out', length=2)
+    ax.grid(which='major', linestyle='-', linewidth=0.5, alpha=0.3)
+    ax.grid(which='minor', linestyle=':', linewidth=0.5, alpha=0.15)
+
+
+def plot_realtime(samples, name):
+    """3-panel strip chart mirroring RealtimePlot in the PyQt GUI."""
+    t          = [s['t']         for s in samples]
+    temp_ist   = [s['temp_ist']  for s in samples]
+    temp_soll  = [s['temp_soll'] for s in samples]
+    rate_ist   = [s['rate_ist']  for s in samples]
+    rate_soll  = [s['rate_soll'] for s in samples]
+    power_set  = [s['power_set'] for s in samples]
+    power_eff  = [s['power_eff'] for s in samples]
+
+    fig, (ax_temp, ax_rate, ax_power) = plt.subplots(3, 1, sharex=True, facecolor='white')
+    fig.suptitle(name, fontsize='small')
+
+    ax_temp.plot(t, temp_ist,  '-b', linewidth=1, label='theta_ist')
+    ax_temp.plot(t, temp_soll, '-r', linewidth=1, label='theta_soll')
+    ax_temp.set_ylabel('Temp [°C]')
+    ax_temp.legend(loc='upper left', fontsize='small')
+
+    ax_rate.plot(t, rate_ist,  '-b', linewidth=1, label='heatrate_ist')
+    ax_rate.plot(t, rate_soll, '-r', linewidth=1, label='heatrate_soll')
+    ax_rate.set_ylabel('Rate [K/min]')
+    ax_rate.legend(loc='upper left', fontsize='small')
+
+    ax_power.plot(t, power_set, '-r', linewidth=1, label='power_set')
+    ax_power.plot(t, power_eff, '-b', linewidth=1, label='power_eff')
+    ax_power.set_ylabel('Power [W]')
+    ax_power.set_xlabel('t [s]')
+    ax_power.legend(loc='upper left', fontsize='small')
+
+    for ax in (ax_temp, ax_rate, ax_power):
+        _style_axis(ax)
+
+    ax_temp.label_outer()
+    ax_rate.label_outer()
+
+    fig.tight_layout()
+    return fig
+
+
+def plot_forecast(forecast, samples, name):
+    """Forecast-vs-actual comparison mirroring SudForecastPlot in the PyQt GUI."""
+    t_min_fc = [t / 60.0 for t in forecast['T']]
+    theta_fc  = forecast['Theta']
+    finished  = forecast['Finished']
+
+    t_min_actual = [s['t'] / 60.0  for s in samples]
+    theta_actual  = [s['temp_ist'] for s in samples]
+
+    fig, ax = plt.subplots(1, 1, facecolor='white')
+
+    ax.plot(t_min_actual, theta_actual, '-b', linewidth=1.5, zorder=2, label='actual')
+    ax.plot(t_min_fc,    theta_fc,      '-b', linewidth=1.5, alpha=0.5, zorder=2, label='forecast')
+
+    total = t_min_fc[-1] if t_min_fc else 0.0
+    suffix = '' if finished else ' so far'
+    ax.set_title('{} - {:.0f} min{} total'.format(name, total, suffix), fontsize='small')
+    ax.set_xlabel('t [min]')
+    ax.set_ylabel('Temp [°C]')
+    ax.legend(loc='upper left', fontsize='small')
+    _style_axis(ax)
+
+    fig.tight_layout()
+    return fig
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument('date_time', help='Timestamp part of the filename, e.g. 20260628T184903')
+    parser.add_argument('sud_name',  help='Sud name part of the filename, e.g. Sud-0010')
+    default_log_dir = Path(__file__).parent.parent / 'logs'
+    parser.add_argument('--log-dir', default=str(default_log_dir),
+                        help='Directory containing the log files (default: %(default)s)')
+    args = parser.parse_args()
+
+    log_dir = Path(args.log_dir)
+    stem = '{}_{}'.format(args.date_time, args.sud_name)
+    log_path      = log_dir / 'log_{}.json'.format(stem)
+    forecast_path = log_dir / 'forecast_{}.json'.format(stem)
+
+    for path in (log_path, forecast_path):
+        if not path.exists():
+            print('Error: file not found: {}'.format(path), file=sys.stderr)
+            sys.exit(1)
+
+    with open(log_path) as f:
+        log = json.load(f)
+    with open(forecast_path) as f:
+        forecast = json.load(f)
+
+    name = log.get('Name', stem)
+    samples = log['Samples']
+
+    plot_realtime(samples, name)
+    plot_forecast(forecast, samples, name)
+
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()