diff --git a/cfast_slic.pxd b/cfast_slic.pxd
index fc422cb..0b3de23 100644
--- a/cfast_slic.pxd
+++ b/cfast_slic.pxd
@@ -42,6 +42,7 @@ cdef extern from "src/context.h" namespace "fslic":
         float preemptive_thres
 
         bool manhattan_spatial_dist
+        bool debug_mode
 
         BaseContext(int H, int W, int K, const uint8_t* image, Cluster *clusters) except +
         void initialize_clusters() nogil
@@ -49,6 +50,7 @@ cdef extern from "src/context.h" namespace "fslic":
         bool parallelism_supported() nogil
         void iterate(uint16_t *assignment, int max_iter) nogil except +
         string get_timing_report();
+        string get_recorder_report();
 
     cdef cppclass Context(BaseContext[uint16_t]):
         Context(int H, int W, int K, const uint8_t* image, Cluster *clusters) except +
@@ -111,8 +113,11 @@ cdef class SlicModel:
     cdef public object preemptive
     cdef public float preemptive_thres
     cdef public object manhattan_spatial_dist
+    cdef public object debug_mode
+
     cdef public object float_color
     cdef public object last_timing_report
+    cdef public object last_recorder_report
 
     cpdef void initialize(self, const uint8_t [:, :, ::1] image)
     cpdef iterate(self, const uint8_t [:, :, ::1] image, int max_iter, float compactness, float min_size_factor, uint8_t subsample_stride)
diff --git a/cfast_slic.pyx b/cfast_slic.pyx
index 06a5c66..79bb0d3 100644
--- a/cfast_slic.pyx
+++ b/cfast_slic.pyx
@@ -33,6 +33,7 @@ cdef class SlicModel:
         self.real_dist_type = "standard"
         self.convert_to_lab = False
         self.float_color = True
+        self.debug_mode = False
 
         self._c_clusters = <cfast_slic.Cluster *>malloc(sizeof(cfast_slic.Cluster) * num_components)
         memset(self._c_clusters, 0, sizeof(cfast_slic.Cluster) * num_components)
@@ -183,6 +184,7 @@ cdef class SlicModel:
                 context.preemptive = self.preemptive
                 context.preemptive_thres = self.preemptive_thres
                 context.manhattan_spatial_dist = self.manhattan_spatial_dist
+                context.debug_mode = self.debug_mode
                 with nogil:
                     context.initialize_state()
                     context.iterate(
@@ -191,6 +193,7 @@ cdef class SlicModel:
                     )
             finally:
                 self.last_timing_report = context.get_timing_report().decode("utf-8")
+                self.last_recorder_report = context.get_recorder_report()
                 del context
         else:
             if self.real_dist_type == 'standard':
@@ -241,6 +244,7 @@ cdef class SlicModel:
                 context_real_dist.preemptive = self.preemptive
                 context_real_dist.preemptive_thres = self.preemptive_thres
                 context_real_dist.manhattan_spatial_dist = self.manhattan_spatial_dist
+                context_real_dist.debug_mode = self.debug_mode
                 with nogil:
                     context_real_dist.initialize_state()
                     context_real_dist.iterate(
@@ -249,6 +253,7 @@ cdef class SlicModel:
                     )
             finally:
                 self.last_timing_report = context_real_dist.get_timing_report().decode("utf-8")
+                self.last_recorder_report = context_real_dist.get_recorder_report()
                 del context_real_dist
         result = assignments.astype(np.int16)
         result[result == 0xFFFF] = -1
diff --git a/fast_slic/base_slic.py b/fast_slic/base_slic.py
index 5e8c13c..65e36d8 100644
--- a/fast_slic/base_slic.py
+++ b/fast_slic/base_slic.py
@@ -13,6 +13,7 @@ def __init__(self,
                  preemptive=False,
                  preemptive_thres=0.05,
                  manhattan_spatial_dist=False,
+                 debug_mode=False,
                  num_threads=-1):
         self.compactness = compactness
         self.subsample_stride = subsample_stride
@@ -25,6 +26,7 @@ def __init__(self,
         self._slic_model.preemptive_thres = preemptive_thres
         self._slic_model.manhattan_spatial_dist = manhattan_spatial_dist
         self._slic_model.num_threads = num_threads
+        self._slic_model.debug_mode = debug_mode
 
     @property
     def convert_to_lab(self):
diff --git a/src/context.cpp b/src/context.cpp
index fb4e74f..3198098 100644
--- a/src/context.cpp
+++ b/src/context.cpp
@@ -153,7 +153,8 @@ namespace fslic {
                 before_iteration();
             }
             preemptive_grid.initialize(clusters, preemptive, preemptive_thres, subsample_stride);
-
+            recorder.initialize(debug_mode);
+            recorder.push(-1, this->assignment, this->min_dists, this->clusters);
             for (int i = 0; i < max_iter; i++) {
                 {
                     fstimer::Scope s("assign");
@@ -169,6 +170,7 @@ namespace fslic {
                     fstimer::Scope s("after_update");
                     after_update();
                 }
+                recorder.push(i, this->assignment, this->min_dists, this->clusters);
                 subsample_rem = (subsample_rem + 1) % subsample_stride;
             }
             preemptive_grid.finalize(clusters);
diff --git a/src/context.h b/src/context.h
index b9d04b1..b2de09e 100644
--- a/src/context.h
+++ b/src/context.h
@@ -15,6 +15,7 @@
 #include "simd-helper.hpp"
 #include "fast-slic-common.h"
 #include "preemptive.h"
+#include "recorder.h"
 
 typedef std::chrono::high_resolution_clock Clock;
 
@@ -32,6 +33,7 @@ namespace fslic {
         float preemptive_thres = 0.01;
 
         bool manhattan_spatial_dist = true;
+        bool debug_mode = false;
     protected:
         int H, W, K;
         const uint8_t* image;
@@ -50,6 +52,7 @@ namespace fslic {
         simd_helper::AlignedArray<DistType> spatial_dist_patch;
 
         PreemptiveGrid preemptive_grid;
+        Recorder<DistType> recorder;
     public:
         std::string last_timing_report;
     public:
@@ -59,7 +62,8 @@ namespace fslic {
               assignment(H, W, S, S, S, S),
               min_dists(H, W, S, S, S, S),
               spatial_dist_patch(2 * S + 1, 2 * S + 1),
-              preemptive_grid(H, W, K, S) {};
+              preemptive_grid(H, W, K, S),
+              recorder(H, W, K) {};
         virtual ~BaseContext();
     public:
         void initialize_clusters();
@@ -68,6 +72,7 @@ namespace fslic {
         bool parallelism_supported();
         void iterate(uint16_t *assignment, int max_iter);
         std::string get_timing_report() { return last_timing_report; };
+        std::string get_recorder_report() { return recorder.get_report(); };
     private:
         void prepare_spatial();
         void assign();
diff --git a/src/recorder.h b/src/recorder.h
new file mode 100644
index 0000000..3d4e6d5
--- /dev/null
+++ b/src/recorder.h
@@ -0,0 +1,103 @@
+#ifndef _FAST_SLIC_RECORDER_H
+#define _FAST_SLIC_RECORDER_H
+#include <vector>
+#include <string>
+#include <cstdint>
+#include <sstream>
+#include <algorithm>
+#include "simd-helper.hpp"
+
+namespace fslic {
+    template <class DistType>
+    struct RecorderSnapshot {
+        int iteration;
+        std::vector<uint16_t> assignment;
+        std::vector<DistType> min_dists;
+        std::vector<Cluster> clusters;
+
+        void gen(std::stringstream& stream) {
+            stream << "{\"iteration\": " << iteration;
+            stream << ", \"clusters\": [";
+
+            for (int i = 0; i < (int)clusters.size(); i++) {
+                Cluster &cluster = clusters[i];
+                if (i > 0) stream << ",";
+                stream << "{\"yx\": [" << cluster.y << "," << cluster.x << "]";
+                stream << ", \"color\": [" << cluster.r << "," << cluster.g << "," << cluster.b << "]";
+                stream << ", \"is_updatable\": " << (int)cluster.is_updatable;
+                stream << ", \"is_active\": " << (int)cluster.is_active;
+                stream << ", \"number\": " << cluster.number;
+                stream << ", \"num_members\": " << cluster.num_members;
+                stream << "}";
+            }
+            stream << "]";
+            stream << ", \"assignment\": [";
+            for (int i = 0; i < (int)assignment.size(); i++) {
+                if (i > 0) stream << ",";
+                stream << assignment[i];
+            }
+            stream << "]";
+            stream << ", \"min_dists\": [";
+            for (int i = 0; i < (int)min_dists.size(); i++) {
+                if (i > 0) stream << ",";
+                stream << min_dists[i];
+            }
+            stream << "]";
+            stream << "}";
+        }
+    };
+
+    template <class DistType>
+    class Recorder {
+    private:
+        std::vector<RecorderSnapshot<DistType>> snapshots;
+        int H, W, K;
+        bool enabled;
+    public:
+        Recorder(int H, int W, int K) : H(H), W(W), K(K), enabled(false) {};
+        void initialize(bool enabled) {
+            this->enabled = enabled;
+        }
+        void push(
+            int iter,
+            const simd_helper::AlignedArray<uint16_t> &assignment,
+            const simd_helper::AlignedArray<DistType> &min_dists,
+                const Cluster *clusters) {
+            if (!enabled) return;
+            RecorderSnapshot<DistType> snapshot;
+            snapshot.iteration = iter;
+            snapshot.assignment.resize(H * W);
+            snapshot.min_dists.resize(H * W);
+            snapshot.clusters.resize(K);
+
+            for (int i = 0; i < H; i++) {
+                for (int j = 0; j < W; j++) {
+                    snapshot.assignment[W * i + j] = assignment.get(i, j);
+                    snapshot.min_dists[W * i + j] = min_dists.get(i, j);
+                }
+            }
+            std::copy(clusters, clusters + K, snapshot.clusters.begin());
+            snapshots.push_back(snapshot);
+        }
+
+        std::string get_report() {
+            std::stringstream stream;
+            gen(stream);
+            return stream.str();
+        }
+
+    private:
+        void gen(std::stringstream& stream) {
+            stream << "{\"height\": " << H;
+            stream << ", \"width\": " << W;
+            stream << ", \"snapshots\": [";
+            for (int i = 0; i < (int)snapshots.size(); i++) {
+                if (i > 0) stream << ",";
+                snapshots[i].gen(stream);
+            }
+            stream << "]}";
+        }
+    };
+}
+
+#endif