diff --git a/src/main/flatbuffers/cflamegraph_schema.fbs b/src/main/flatbuffers/cflamegraph_schema.fbs
index 65f4a823..3eec7061 100644
--- a/src/main/flatbuffers/cflamegraph_schema.fbs
+++ b/src/main/flatbuffers/cflamegraph_schema.fbs
@@ -1,5 +1,7 @@
 namespace com.github.kornilova_l.flamegraph.cflamegraph;
 
+// Contains the same information as flamegraph format
+
 table Names {
   class_names:[string];
   method_names:[string];
@@ -10,8 +12,8 @@ struct Node {
   class_name_id:int; // -1 if class name is not set
   method_name_id:int;
   description_id:int; // -1 if description is not set
-  width:int;
-  depth:int;
+  width:int; // cannot be 0
+  depth:int; // depth starts with 1
 }
 
 table Tree {
diff --git a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/CompressedFlamegraphToCallTracesConverter.kt b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/CompressedFlamegraphToCallTracesConverter.kt
index 7b1629da..cafe168e 100644
--- a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/CompressedFlamegraphToCallTracesConverter.kt
+++ b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/CompressedFlamegraphToCallTracesConverter.kt
@@ -13,17 +13,17 @@ import java.io.File
  * It uses FlatBuffers for data serialization and does not duplicate
  * class names, method names and descriptions.
  *
- * See scheme in /src/main/flatbuffers/cflamegraph_schema.fbs
+ * See schema in /src/main/flatbuffers/cflamegraph_schema.fbs
  *
  * Example:
  * ._ _
- * |c|d|___ _
- * |b()____|e|_______ _
- * |Class.a__________|f|
+ * |c|d|____ _
+ * |void b()|e|_______ _
+ * |Class.a___________|f|
  *
  * In original flamegraph format this example would look like this:
  * a;b();c 5
- * a;b();d 5
+ * a;void b();d 5
  * a;b() 10
  * a;e 5
  * a 50
@@ -33,7 +33,7 @@ import java.io.File
  * Names: {
  *   classNames: ["Class"],
  *   methodNames: ["a", "b", "c", "d", "e", "f"],
- *   descriptions: ["()"]
+ *   descriptions: ["()void"]
  * }
  * Tree: {
  *   nodes: [
diff --git a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/Converter.kt b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/Converter.kt
index 665ac112..2ad62d35 100644
--- a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/Converter.kt
+++ b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/cflamegraph/Converter.kt
@@ -1,38 +1,38 @@
 package com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_call_traces.cflamegraph
 
+import com.github.kornilova_l.flamegraph.cflamegraph.Node
+import com.github.kornilova_l.flamegraph.cflamegraph.Tree
 import com.github.kornilova_l.flamegraph.plugin.pleaseReportIssue
 import com.github.kornilova_l.flamegraph.plugin.server.trees.util.TreesUtil
-import com.github.kornilova_l.flamegraph.plugin.server.trees.util.TreesUtil.parsePositiveInt
-import com.github.kornilova_l.flamegraph.plugin.server.trees.util.TreesUtil.parsePositiveLong
 import com.github.kornilova_l.flamegraph.proto.TreeProtos
-import java.io.BufferedReader
 import java.io.File
-import java.io.FileReader
+import java.nio.ByteBuffer
 import java.util.*
-import java.util.regex.Pattern
 
 
 internal class Converter(file: File) {
     val tree: TreeProtos.Tree
-    private val classNames = HashMap<Int, String>()
-    private val methodNames = HashMap<Int, String>()
-    private val descriptions = HashMap<Int, String>()
-    private val headerPattern = Pattern.compile("--[CMD]-- \\d+")
+    private val classNames: Map<Int, String>
+    private val methodNames: Map<Int, String>
+    private val descriptions: Map<Int, String>
     private var maxDepth = 0
 
     init {
         val tree = createEmptyTree()
+        val cflamegraphTree = Tree.getRootAsTree(ByteBuffer.wrap(file.readBytes()))
+
+        val names = cflamegraphTree.names()
+        classNames = convertNamesToMap(names.classNamesLength()) { names.classNames(it) }
+        methodNames = convertNamesToMap(names.methodNamesLength()) { names.methodNames(it) }
+        descriptions = convertNamesToMap(names.descriptionsLength()) { names.descriptions(it) }
+
         val currentStack = ArrayList<TreeProtos.Tree.Node.Builder>()
         currentStack.add(tree.baseNodeBuilder)
-        BufferedReader(FileReader(file), 1000 * 8192).use { reader ->
-            var line: String? = initMaps(reader)
-            while (line != null) {
-                if (line.isNotBlank()) {
-                    processLine(line, currentStack)
-                }
-                line = reader.readLine()
-            }
+
+        for (i in 0 until cflamegraphTree.nodesLength()) {
+            processNode(cflamegraphTree.nodes(i), currentStack)
         }
+
         tree.depth = maxDepth
         TreesUtil.setNodesOffsetRecursively(tree.baseNodeBuilder, 0)
         TreesUtil.setTreeWidth(tree)
@@ -40,70 +40,28 @@ internal class Converter(file: File) {
         this.tree = tree.build()
     }
 
-    private fun initMaps(reader: BufferedReader): String {
-        var line = reader.readLine()
-        while (line.isEmpty() || headerPattern.matcher(line).matches()) {
-            if (line.isEmpty()) {
-                line = reader.readLine()
-                continue
-            }
-            val linesCount = Integer.parseInt(line.substring(6))
-            val value = line[2]
-            val currentMap = when (value) {
-                'C' -> classNames
-                'M' -> methodNames
-                'D' -> descriptions
-                else ->
-                    /* this should never happen because we checked line with regexp */
-                    throw IllegalArgumentException("$pleaseReportIssue: Cannot read header $line")
-            }
-            for (i in 0 until linesCount) {
-                val mapLine = reader.readLine()
-                val lastSpacePos = mapLine.lastIndexOf(' ')
-                val id = parsePositiveInt(mapLine, lastSpacePos + 1, mapLine.length)
-                val name = mapLine.substring(0, lastSpacePos)
-                currentMap[id] = name
-            }
-            line = reader.readLine()
+    private fun convertNamesToMap(itemsCount: Int, getter: (Int) -> String): Map<Int, String> {
+        val map = HashMap<Int, String>()
+        for (i in 0 until itemsCount) {
+            map[i] = getter(i)
         }
-        return line
+        return map
     }
 
-    private fun processLine(line: String,
+    private fun processNode(node: Node,
                             currentStack: ArrayList<TreeProtos.Tree.Node.Builder>) {
-        var className: String? = null
-        var methodName: String? = null
-        var desc: String? = null
-        var width = -1L
-        var depth = -1
-        var i = 0
-        while (i < line.length - 1) {
-            val c = line[i]
-            val endOfNumPos = getNextEndOfNum(line, i + 2)
-            when (c) {
-                'C' -> className = classNames[getParamIntValue(line, i, endOfNumPos)]!!
-                'M' -> methodName = methodNames[getParamIntValue(line, i, endOfNumPos)]!!
-                'D' -> desc = descriptions[getParamIntValue(line, i, endOfNumPos)]!!
-                'd' -> depth = getParamIntValue(line, i, endOfNumPos)
-                'w' -> width = getParamLongValue(line, i, endOfNumPos)
-            }
-            i = endOfNumPos
-        }
-        if (depth == -1 || width == -1L) {
-            throw IllegalArgumentException("$pleaseReportIssue: Cannot find depth or width value in line: $line")
-        }
-        if (methodName == null) {
-            throw IllegalArgumentException("$pleaseReportIssue: Line must contain method name: $line")
-        }
-        while (depth < currentStack.size) { // if some calls are finished
+        validateNode(node)
+
+        while (node.depth() < currentStack.size) { // if some calls are finished
             currentStack.removeAt(currentStack.size - 1)
         }
+
         val newNode = TreesUtil.updateNodeList(
                 currentStack[currentStack.size - 1],
-                className ?: "",
-                methodName,
-                desc ?: "",
-                width
+                if (node.classNameId() >= 0) classNames[node.classNameId()]!! else "",
+                methodNames[node.methodNameId()]!!,
+                if (node.descriptionId() >= 0) descriptions[node.descriptionId()]!! else "",
+                node.width().toLong()
         )
         currentStack.add(newNode)
         if (currentStack.size - 1 > maxDepth) {
@@ -111,21 +69,10 @@ internal class Converter(file: File) {
         }
     }
 
-    private fun getParamIntValue(line: String, paramPos: Int, endOfNumPos: Int): Int {
-        return parsePositiveInt(line, paramPos + 1, endOfNumPos)
-    }
-
-    private fun getParamLongValue(line: String, paramPos: Int, endOfNumPos: Int): Long {
-        return parsePositiveLong(line, paramPos + 1, endOfNumPos)
-    }
-
-    private fun getNextEndOfNum(line: String, startIndex: Int): Int {
-        for (i in startIndex until line.length) {
-            if (line[i] !in '0'..'9') {
-                return i
-            }
-        }
-        return line.length
+    private fun validateNode(node: Node) {
+        require(node.depth() > 0) { "$pleaseReportIssue: node depth must be bigger than 0." }
+        require(node.width() > 0) { "$pleaseReportIssue: node width must be bigger than 0." }
+        require(node.methodNameId() >= 0) { "$pleaseReportIssue: node method name id must be set." }
     }
 
     private fun createEmptyTree(): TreeProtos.Tree.Builder {
diff --git a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/yourkit_csv/YourkitCsvToCallTracesConverter.kt b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/yourkit_csv/YourkitCsvToCallTracesConverter.kt
index a0b59517..e4bf5a2f 100644
--- a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/yourkit_csv/YourkitCsvToCallTracesConverter.kt
+++ b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_call_traces/yourkit_csv/YourkitCsvToCallTracesConverter.kt
@@ -2,17 +2,14 @@ package com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_call_
 
 import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_call_traces.FileToCallTracesConverter
 import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_file.ProfilerToFlamegraphConverter
-import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_file.yourkit_csv.YourkitCsvToCFlamegraphConverter
 import com.github.kornilova_l.flamegraph.proto.TreeProtos.Tree
 import java.io.BufferedReader
 import java.io.File
 import java.io.FileReader
 
 
-/**
- * This converter is no longer supported.
- * When new csv file is added it is converted with [YourkitCsvToCFlamegraphConverter]
- */
+@Deprecated("When a new csv file is added it's converted with YourkitCsvToCFlamegraphConverter. " +
+        "This converter is to support already uploaded csv files.")
 class YourkitCsvToCallTracesConverter : FileToCallTracesConverter() {
     override fun getId(): String {
         return "yourkit"
diff --git a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/ProfilerToCompressedFlamegraphConverter.kt b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/ProfilerToCompressedFlamegraphConverter.kt
index 48cf8a26..4d6b3b38 100644
--- a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/ProfilerToCompressedFlamegraphConverter.kt
+++ b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/ProfilerToCompressedFlamegraphConverter.kt
@@ -1,65 +1,67 @@
 package com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_file
 
+import com.github.kornilova_l.flamegraph.cflamegraph.Names
+import com.github.kornilova_l.flamegraph.cflamegraph.Node
+import com.github.kornilova_l.flamegraph.cflamegraph.Tree
 import com.github.kornilova_l.flamegraph.plugin.server.FileToFileConverterFileSaver
+import com.google.flatbuffers.FlatBufferBuilder
 import com.intellij.openapi.extensions.ExtensionPointName
-import java.io.BufferedWriter
 import java.io.File
-import java.io.FileWriter
+import java.io.FileOutputStream
 
 
 class CompressedFlamegraphFileSaver : FileToFileConverterFileSaver() {
     override val extension = ProfilerToCompressedFlamegraphConverter.cFlamegraphExtension
 
     override fun tryToConvert(file: File): Boolean {
-        val cFlamegraph = ProfilerToCompressedFlamegraphConverter.convert(file)
-        if (cFlamegraph != null) {
-            BufferedWriter(FileWriter(file)).use { writer ->
-                writeMap(cFlamegraph.classNames, writer, 'C')
-                writeMap(cFlamegraph.methodNames, writer, 'M')
-                writeMap(cFlamegraph.descriptions, writer, 'D')
-                for (line in cFlamegraph.lines) {
-                    if (line.classNameId != null) {
-                        writer.write("C")
-                        writer.write(line.classNameId.toString())
-                    }
-                    writer.write("M")
-                    writer.write(line.methodNameId.toString())
-                    if (line.descId != null) {
-                        writer.write("D")
-                        writer.write(line.descId.toString())
-                    }
-                    writer.write("d")
-                    writer.write(line.depth.toString())
-                    writer.write("w")
-                    writer.write(line.width.toString())
-                    writer.write("\n")
-                }
-            }
-            return true
+        val cFlamegraph = ProfilerToCompressedFlamegraphConverter.convert(file) ?: return false
+        val builder = FlatBufferBuilder(1024)
+
+        val classNamesOffsets = IntArray(cFlamegraph.classNames.size)
+        for (i in 0 until cFlamegraph.classNames.size) {
+            classNamesOffsets[i] = builder.createString(cFlamegraph.classNames[i])
         }
-        return false
-    }
+        val classNames = Names.createClassNamesVector(builder, classNamesOffsets)
+
+        val methodNamesOffsets = IntArray(cFlamegraph.methodNames.size)
+        for (i in 0 until cFlamegraph.methodNames.size) {
+            methodNamesOffsets[i] = builder.createString(cFlamegraph.methodNames[i])
+        }
+        val methodNames = Names.createMethodNamesVector(builder, methodNamesOffsets)
+
+        val descriptionsOffsets = IntArray(cFlamegraph.descriptions.size)
+        for (i in 0 until cFlamegraph.descriptions.size) {
+            descriptionsOffsets[i] = builder.createString(cFlamegraph.descriptions[i])
+        }
+        val descriptions = Names.createDescriptionsVector(builder, descriptionsOffsets)
+
+        val names = Names.createNames(builder, classNames, methodNames, descriptions)
 
-    private fun writeMap(map: Map<String, Int>, writer: BufferedWriter, letter: Char) {
-        if (map.isNotEmpty()) {
-            writer.write("--$letter-- ${map.size}\n")
-            for (entry in map.entries) {
-                writer.write(entry.key)
-                writer.write(" ")
-                writer.write(entry.value.toString())
-                writer.write("\n")
-            }
+        Tree.startNodesVector(builder, cFlamegraph.lines.size)
+        for (i in cFlamegraph.lines.size - 1 downTo 0) {
+            val line = cFlamegraph.lines[i]
+            Node.createNode(builder, line.classNameId ?: -1, line.methodNameId,
+                    line.descId ?: -1, line.width, line.depth)
         }
+        val nodes = builder.endVector()
+
+        val tree = Tree.createTree(builder, names, nodes)
+
+        builder.finish(tree)
+        FileOutputStream(file).write(builder.sizedByteArray())
+
+        return true
     }
 }
 
+@Suppress("ArrayInDataClass") // Instances of the class will not be compared
 data class CFlamegraph(val lines: List<CFlamegraphLine>,
-                       val classNames: Map<String, Int>,
-                       val methodNames: Map<String, Int>,
-                       val descriptions: Map<String, Int>)
+                       val classNames: Array<String>, // a "map" from id to class name
+                       val methodNames: Array<String>, // a "map" from id to method name
+                       val descriptions: Array<String>) // a "map" from id to description
 
 
-data class CFlamegraphLine(val classNameId: Int?, val methodNameId: Int, val descId: Int?, val width: Long, val depth: Int)
+data class CFlamegraphLine(val classNameId: Int?, val methodNameId: Int, val descId: Int?, val width: Int, val depth: Int)
 
 abstract class ProfilerToCompressedFlamegraphConverter {
     companion object {
diff --git a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/yourkit_csv/Converter.kt b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/yourkit_csv/Converter.kt
index e9cee33b..78f40783 100644
--- a/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/yourkit_csv/Converter.kt
+++ b/src/main/java/com/github/kornilova_l/flamegraph/plugin/server/converters/file_to_file/yourkit_csv/Converter.kt
@@ -4,7 +4,6 @@ import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_call_t
 import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_file.CFlamegraph
 import com.github.kornilova_l.flamegraph.plugin.server.converters.file_to_file.CFlamegraphLine
 import com.github.kornilova_l.flamegraph.plugin.server.trees.util.TreesUtil.parsePositiveInt
-import com.github.kornilova_l.flamegraph.plugin.server.trees.util.TreesUtil.parsePositiveLong
 import java.io.BufferedReader
 import java.io.File
 import java.io.FileReader
@@ -26,7 +25,15 @@ class Converter(file: File) {
                 line = reader.readLine()
             }
         }
-        cFlamegraph = CFlamegraph(cFlamegraphLines, classNames, methodNames, descriptions)
+        cFlamegraph = CFlamegraph(cFlamegraphLines, toArray(classNames), toArray(methodNames), toArray(descriptions))
+    }
+
+    private fun toArray(names: HashMap<String, Int>): Array<String> {
+        val array = Array(names.size) { "" }
+        for (entry in names) {
+            array[entry.value] = entry.key
+        }
+        return array
     }
 
     private fun processLine(line: String) {
@@ -38,13 +45,13 @@ class Converter(file: File) {
         if (!name.contains('(')) {
             return
         }
-        var width = -1L
+        var width = -1
         var depth = -1
         try {
             /* find next delimiter */
             for (i in delimPos + 1 until line.length - 2) {
                 if (line[i] == '"' && line[i + 1] == ',' && line[i + 2] == '"') {
-                    width = parsePositiveLong(line, delimPos + 3, i)
+                    width = parsePositiveInt(line, delimPos + 3, i)
                     depth = parsePositiveInt(line, i + 3, line.length - 1)
                     break
                 }
@@ -52,7 +59,7 @@ class Converter(file: File) {
         } catch (e: NumberFormatException) {
             e.printStackTrace()
         }
-        if (width == -1L || depth == -1) {
+        if (width == -1 || depth == -1) {
             return
         }
         depth -= 1 // after this depth of first call is 1
diff --git a/src/test/java/com/github/kornilova_l/flamegraph/plugin/server/trees/converters/CompressedFlamegraphToCallTracesConverterTest.kt b/src/test/java/com/github/kornilova_l/flamegraph/plugin/server/trees/converters/CompressedFlamegraphToCallTracesConverterTest.kt
deleted file mode 100644
index a7d95403..00000000
--- a/src/test/java/com/github/kornilova_l/flamegraph/plugin/server/trees/converters/CompressedFlamegraphToCallTracesConverterTest.kt
+++ /dev/null
@@ -1,131 +0,0 @@
-package com.github.kornilova_l.flamegraph.plugin.server.trees.converters
-
-import com.github.kornilova_l.flamegraph.plugin.PluginFileManager
-import com.github.kornilova_l.flamegraph.plugin.server.FilesUploaderTest
-import com.github.kornilova_l.flamegraph.plugin.server.trees.GetTreesTest
-import com.github.kornilova_l.flamegraph.plugin.server.trees.TestHelper
-import com.github.kornilova_l.flamegraph.proto.TreeProtos
-import com.intellij.testFramework.fixtures.LightPlatformCodeInsightFixtureTestCase
-import java.io.ByteArrayInputStream
-import java.io.File
-
-private const val simpleFileContent = """
---M-- 6
-a 0
-b 1
-c 2
-d 3
-e 4
-f 5
-M0w100d1
-M1w40d2
-M2w5d3
-M3w5d3
-M4w5d2
-M5w5d1
-"""
-
-private const val fileWithParameters = """
---M-- 6
-a 0
-b 1
-c 2
-d 3
-e 4
-f 5
---D-- 5
-(a, b) 0
-(c) 1
-(hello) 2
-() 3
-(e, se, ef) 4
-M0D0w100d1
-M1D1w40d2
-M2D2w5d3
-M3D3w5d3
-M4D4w5d2
-M5D3w5d1
-"""
-
-private const val mixedContent = """
---M-- 6
-a 0
-b 1
-c 2
-d 3
-e 4
-f 5
---C-- 1
-Class 0
---D-- 5
-(a, b)retVal 0
-(hello) 1
-(hello)ret 2
-()myRetVal 3
-(e, se, ef) 4
-
-M0D0w100d1
-C0M1w40d2
-C0M2D1w5d3
-C0M2D2w5d3
-M3D3w5d3
-M4D4w5d2
-M5w5d1
-"""
-
-private const val stacktracesAreNotMerged = """
---M-- 3
-a 0
-b 1
-c 2
-
-M0w100d1
-M1w10d2
-M2w5d3
-M1w5d2
-M0w100d1
-M1w10d2
-"""
-
-class CompressedFlamegraphToCallTracesConverterTest : LightPlatformCodeInsightFixtureTestCase() {
-
-    private val pathToFolder = "src/test/resources/com/github/kornilova_l/flamegraph/plugin/server/trees/converters"
-
-    fun testSimpleFile() {
-        doTest("simpleFile.cflamegraph",
-                simpleFileContent.toByteArray(),
-                File("$pathToFolder/simple-cflamegraph-result.txt")
-        )
-    }
-
-    fun testFileWithParameters() {
-        doTest("fileWithParameters.cflamegraph",
-                fileWithParameters.toByteArray(),
-                File("$pathToFolder/with-parameters-cflamegraph-result.txt")
-        )
-    }
-
-    fun testFileWithMixedContent() {
-        doTest("fileWithMixedContent.cflamegraph",
-                mixedContent.toByteArray(),
-                File("$pathToFolder/mixed-content-cflamegraph-result.txt")
-        )
-    }
-
-    fun testFileWhereStacktracesAreNotMerged() {
-        doTest("fileWhereStacktracesAreNotMerged.cflamegraph",
-                stacktracesAreNotMerged.toByteArray(),
-                File("$pathToFolder/stacktraces-are-not-merged-result.txt")
-        )
-    }
-
-    private fun doTest(fileName: String, content: ByteArray, expectedResult: File) {
-        PluginFileManager.deleteAllUploadedFiles()
-        FilesUploaderTest.sendFile(fileName, content)
-        val bytes = GetTreesTest.sendRequestForCallTraces(fileName)
-        assertNotNull(bytes)
-        TestHelper.compare(
-                TreeProtos.Tree.parseFrom(ByteArrayInputStream(bytes)).toString(),
-                expectedResult)
-    }
-}
\ No newline at end of file