diff --git a/core/json/src/JsonReader.cpp b/core/json/src/JsonReader.cpp
index d786721..e174993 100644
--- a/core/json/src/JsonReader.cpp
+++ b/core/json/src/JsonReader.cpp
@@ -78,6 +78,7 @@ class JsonReaderImpl {
         return start;
     }
 
+#ifdef NGREST_JSON_NO_QUOTE_STRING
     inline char* tokenString() {
         ++curr; // skip '"'
         char* start = curr;
@@ -99,6 +100,94 @@ class JsonReaderImpl {
         ++curr;
         return start;
     }
+#else
+
+    inline char fromHexChar(short hex)
+    {
+        static const char table[256] = {
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x00
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x10
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x20
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x30
+            0x10, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x40
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x50
+            0x10, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x60
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x70
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x80
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // x90
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // xA0
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // xB0
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // xC0
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // xD0
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // xE0
+            0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10  // xF0
+        };
+        NGREST_ASSERT(table[hex] != 0x10, "Unexpected character while reading unicode hex digit");
+        return table[hex];
+    }
+
+    inline char* tokenString() {
+        ++curr; // skip '"'
+        char* start = curr;
+        char* out = nullptr;
+        while (*curr != '"') {
+            if (*curr == '\\') { // parse quoted characters
+                if (!out) {
+                    out = curr;
+                }
+                ++curr;
+                switch (*curr) {
+                case 'b':
+                    *out = '\b';
+                    break;
+                case 'f':
+                    *out = '\f';
+                    break;
+                case 'n':
+                    *out = '\n';
+                    break;
+                case 'r':
+                    *out = '\r';
+                    break;
+                case 't':
+                    *out = '\t';
+                    break;
+                case 'u':
+                    ++curr;
+                    *out = fromHexChar(*curr) << 4;
+                    ++curr;
+                    *out |= fromHexChar(*curr);
+                    if (*out) { // \u00XX
+                        ++out;
+                    }
+                    ++curr;
+                    *out = fromHexChar(*curr) << 4;
+                    ++curr;
+                    *out |= fromHexChar(*curr);
+                    break;
+                default:
+                    *out = *curr;
+                    break;
+                }
+                ++out;
+            } else {
+                NGREST_ASSERT(*curr >= 0x20, "Unexpected control character while reading string");
+                if (out) {
+                    *out = *curr;
+                    ++out;
+                }
+            }
+            ++curr;
+        }
+        if (out) {
+            *out = '\0';
+        } else {
+            *curr = '\0';
+        }
+        ++curr;
+        return start;
+    }
+#endif
 
 
     inline JsonReaderImpl(char* buff, MemPool* memPool):
@@ -141,7 +230,7 @@ class JsonReaderImpl {
         if (!strncmp(token, "NaN", len))
             return pool->alloc<Value>(ValueType::NaN);
 
-        NGREST_THROW_ASSERT("Unexpected token");
+        NGREST_THROW_ASSERT(std::string("Unexpected token: [") + token + "]");
     }
 
     inline Node* readArrayOrObject()
@@ -155,7 +244,7 @@ class JsonReaderImpl {
             return readObject();
         }
 
-        NGREST_THROW_ASSERT("Unexpected symbol");
+        NGREST_THROW_ASSERT(std::string("Unexpected symbol: [") + *curr + "]");
     }
 
     inline Array* readArray()
diff --git a/core/json/src/JsonWriter.cpp b/core/json/src/JsonWriter.cpp
index 914685f..dcc67e7 100644
--- a/core/json/src/JsonWriter.cpp
+++ b/core/json/src/JsonWriter.cpp
@@ -41,6 +41,73 @@ class JsonWriterImpl {
     {
     }
 
+    inline char toHexChar(short dec)
+    {
+        static char hexTable[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+        return hexTable[dec];
+    }
+
+    inline void putString(const char* str)
+    {
+        pool->putChar('"');
+#ifdef NGREST_JSON_NO_QUOTE_STRING
+        pool->putCString(str);
+#else
+        size_t len = strlen(str);
+        pool->reserve(len);
+        const char* start = str;
+        const char* curr = str;
+        for (; *curr; ++curr) {
+            if (*curr < 0x20) {
+                if (start) {
+                    if (curr > start) {
+                        pool->putData(start, curr - start);
+                    }
+                }
+                switch (*curr) {
+                case '\b':
+                    pool->putData("\\b", 2);
+                    break;
+                case '\f':
+                    pool->putData("\\f", 2);
+                    break;
+                case '\n':
+                    pool->putData("\\n", 2);
+                    break;
+                case '\r':
+                    pool->putData("\\r", 2);
+                    break;
+                case '\t':
+                    pool->putData("\\t", 2);
+                    break;
+                default:
+                    pool->putData("\\u00", 4);
+                    pool->putChar(toHexChar((*curr >> 4) & 0x0f));
+                    pool->putChar(toHexChar(*curr & 0x0f));
+                    break;
+                }
+                start = curr + 1;
+            } else {
+                if (*curr == '"' || *curr == '\\') {
+                    if (start) {
+                        if (curr > start) {
+                            pool->putData(start, curr - start);
+                        }
+                        start = curr + 1;
+                    }
+
+                    pool->putChar('\\');
+                    pool->putChar(*curr);
+                }
+            }
+        }
+        if (start && curr > start) {
+            pool->putData(start, curr - start);
+        }
+#endif
+        pool->putChar('"');
+    }
+
     inline void writeNode(const Node* node)
     {
         if (!node) {
@@ -56,9 +123,7 @@ class JsonWriterImpl {
             for (const NamedNode* child = object->firstChild; child; child = child->nextSibling) {
                 if (child != object->firstChild)
                     pool->putChar(',');
-                pool->putChar('"');
-                pool->putCString(child->name);
-                pool->putChar('"');
+                putString(child->name);
                 pool->putChar(':');
                 writeNode(child->node);
             }
@@ -86,9 +151,7 @@ class JsonWriterImpl {
                 break;
 
             case ValueType::String:
-                pool->putChar('"');
-                pool->putCString(value->value);
-                pool->putChar('"');
+                putString(value->value);
                 break;
 
             case ValueType::Number:
diff --git a/tests/json/src/jsontest.cpp b/tests/json/src/jsontest.cpp
index 496fbeb..fbc03a0 100644
--- a/tests/json/src/jsontest.cpp
+++ b/tests/json/src/jsontest.cpp
@@ -38,7 +38,7 @@ int main()
         const int testsCount = 8;
         char test1[] = "{}";
         char test2[] = "[]";
-        char test3[] = "{\"abc\": 1}";
+        char test3[] = "{\"ab c\": 1}";
         char test4[] = "{ \"q\": [ ] }";
         char test5[] = "{\"x\": {\"abc\": 1}}";
         char test6[] = "{  \"x\" : {\"abc\": 1 }, \"y\": [1, 2e2, \"3\", null , NaN]}";
@@ -55,26 +55,78 @@ int main()
             test8
         };
 
+        const char* testsOut[testsCount] = {
+            "{}",
+            "[]",
+            "{\"ab c\":1}",
+            "{\"q\":[]}",
+            "{\"x\":{\"abc\":1}}",
+            "{\"x\":{\"abc\":1},\"y\":[1,2e2,\"3\",null,NaN]}",
+            "[{},{\"\":\"\"}]",
+            "[[[],[]],{\"1\":[]}]"
+        };
+
         for (int t = 0; t < testsCount; ++t) {
+            std::cout << "Basic test: #" << t << std::endl;
             ngrest::MemPool pool;
             ngrest::MemPool poolOut;
             ngrest::Node* root = ngrest::json::JsonReader::read(tests[t], &pool);
 
             ngrest::json::JsonWriter::write(root, &poolOut, 2);
 
-            int chunksCount = poolOut.getChunkCount();
-            const ngrest::MemPool::Chunk* chunks = poolOut.getChunks();
-            printf("test #%d \n----------\n", t + 1);
-            for (int i = 0; i < chunksCount; ++i) {
-                const ngrest::MemPool::Chunk* chunk = chunks + i;
-                fwrite(chunk->buffer, chunk->size, 1, stdout);
-            }
-            printf("\n----------\n");
+            const ngrest::MemPool::Chunk* chunk = poolOut.flatten();
+            NGREST_ASSERT(!strcmp(chunk->buffer, testsOut[t]), std::string("Basic Test failed. Expected [")
+                          + testsOut[t] + "] found [" + chunk->buffer + "].")
         }
 
     } catch (const std::exception& e) {
         std::cerr << e.what() << std::endl;
+        return 1;
     }
 
+
+
+    // quoting test
+    try {
+        const char* json = R"(["no special chars","\b\f\n\r\t\"\\\/\u0008\u000a","__\n\r__","\t__","__\t"])";
+        const char* values[] = {
+            "no special chars", "\b\f\n\r\t\"\\/\x08\x0a", "__\n\r__", "\t__", "__\t"
+        };
+        const char* jsonOut = R"(["no special chars","\b\f\n\r\t\"\\/\b\n","__\n\r__","\t__","__\t"])";
+        ngrest::MemPool poolIn;
+
+        // test reader
+        char* jsonIn = poolIn.putCString(json, true);
+        const ngrest::Node* root = ngrest::json::JsonReader::read(jsonIn, &poolIn);
+        NGREST_ASSERT(root->type == ngrest::NodeType::Array, "Read node is not array");
+        const ngrest::Array* arr = static_cast<const ngrest::Array*>(root);
+        int index = 0;
+        for (const ngrest::LinkedNode* node = arr->firstChild; node; node = node->nextSibling, ++index) {
+            std::cout << "Reader test: #" << index << std::endl;
+            NGREST_ASSERT_NULL(node->node);
+            NGREST_ASSERT(node->node->type == ngrest::NodeType::Value, "Child is not Value");
+            const ngrest::Value* value = static_cast<const ngrest::Value*>(node->node);
+            NGREST_ASSERT_NULL(value->value);
+            NGREST_ASSERT(!strcmp(value->value, values[index]), std::string("Reader Test failed. Expected [")
+                          + values[index] + "] found [" + value->value + "].")
+        }
+
+
+        std::cout << "Writer test" << std::endl;
+        // test writer
+        ngrest::MemPool poolOut;
+        ngrest::json::JsonWriter::write(root, &poolOut);
+        ngrest::MemPool::Chunk* res = poolOut.flatten();
+        NGREST_ASSERT_NULL(res);
+        NGREST_ASSERT(!strcmp(res->buffer, jsonOut), std::string("Writer Test failed. Expected:\n===================\n")
+                      + jsonOut + "\n===================\nfound:\n===================\n"
+                      + res->buffer + "\n===================\n")
+    } catch (const std::exception& e) {
+        std::cerr << e.what() << std::endl;
+        return 1;
+    }
+
+    std::cout << "All json tests passed" << std::endl;
+
     return 0;
 }