diff --git a/.gitignore b/.gitignore
index d7182fc..d8eb3ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,8 @@ test/*.pdb
 test/*.ilk
 server/server
 bench/jsonBench
+bench/yamlBench
+bench/bench
 yaml.html
 libyaml.dylib
 libyaml.so
diff --git a/bench/bench.nim b/bench/bench.nim
new file mode 100644
index 0000000..a02a5a5
--- /dev/null
+++ b/bench/bench.nim
@@ -0,0 +1 @@
+import jsonBench, yamlBench
\ No newline at end of file
diff --git a/bench/common.nim b/bench/common.nim
new file mode 100644
index 0000000..4c01a4d
--- /dev/null
+++ b/bench/common.nim
@@ -0,0 +1,18 @@
+import stopwatch
+
+template multiBench*(nanosecs: int64, times: int, body: stmt): stmt =
+    assert(times mod 2 == 0)
+    var arr: array[0..times - 1, int64]
+    for i in countup(0, times - 1):
+        var c: clock
+        bench(c):
+            body
+        arr[i] = c.nanoseconds()
+    sort(arr, cmp)
+    # ignore lowest and highest 10%
+    let tenth: int = times div 10
+    let lowest = arr[tenth]
+    var totaldiff = 0.int64
+    for i in countup(tenth + 1, times - tenth - 1):
+        totaldiff += arr[i] - lowest
+    nanosecs = lowest + totaldiff div (times - 2 * tenth)
\ No newline at end of file
diff --git a/bench/jsonBench.nim b/bench/jsonBench.nim
index d846ed9..06b2867 100644
--- a/bench/jsonBench.nim
+++ b/bench/jsonBench.nim
@@ -1,4 +1,4 @@
-import "../yaml"
+import "../yaml", common
 
 from nimlets_yaml import objKind
 
@@ -6,23 +6,6 @@ import math, strutils, stopwatch, terminal, algorithm
 
 proc cmp(left, right: clock): int = cmp(left.nanoseconds(), right.nanoseconds()) 
 
-template multiBench(nanosecs: int64, times: int, body: stmt): stmt =
-    assert(times mod 2 == 0)
-    var arr: array[0..times - 1, int64]
-    for i in countup(0, times - 1):
-        var c: clock
-        bench(c):
-            body
-        arr[i] = c.nanoseconds()
-    sort(arr, cmp)
-    # ignore lowest and highest 10%
-    let tenth: int = times div 10
-    let lowest = arr[tenth]
-    var totaldiff = 0.int64
-    for i in countup(tenth + 1, times - tenth - 1):
-        totaldiff += arr[i] - lowest
-    nanosecs = lowest + totaldiff div (times - 2 * tenth)
-
 type
     ObjectKind = enum
         otMap, otSequence
diff --git a/bench/nimlets_yaml.nim b/bench/nimlets_yaml.nim
index d264d8c..afd465a 100644
--- a/bench/nimlets_yaml.nim
+++ b/bench/nimlets_yaml.nim
@@ -117,7 +117,7 @@ proc events(self: LoadContext): iterator(): yaml_event_t =
     var event: yaml_event_t
     while true:
       if yaml_parser_parse(addr self.parser, addr event) != 1:
-        raise newException(Exception, "Malformed input: " & $self.parser.error)
+        raise newException(Exception, $self.parser.error & ": " & $self.parser.problem)
 
       if event.typ == YAML_NO_EVENT:
         break
@@ -148,12 +148,11 @@ recognize[YAML_SCALAR_EVENT] = proc(self: LoadContext, event: yaml_event_t): Yam
   of YAML_NULL_TAG: return YamlObj(kind : YamlObjKind.Null)
   of YAML_BOOL_TAG:
     result = YamlObj(kind : YamlObjKind.Bool)
-    if event.data.scalar.value == "true":
-      result.boolVal = true
-    elif event.data.scalar.value == "false":
-      result.boolVal = false
-    else:
-      assert(false, "Unknown boolean value " & $event.data.scalar.value)
+    case $event.data.scalar.value
+    of "true": result.boolVal = true
+    of "false": result.boolVal = false
+    else: assert(false,
+                 "Unknown boolean value \"" & $event.data.scalar.value & '\"')
   of YAML_INT_TAG:
     return YamlObj(kind : YamlObjKind.Int, intVal : parseInt($event.data.scalar.value))
   of YAML_FLOAT_TAG:
diff --git a/bench/yamlBench.nim b/bench/yamlBench.nim
new file mode 100644
index 0000000..88fbe3a
--- /dev/null
+++ b/bench/yamlBench.nim
@@ -0,0 +1,191 @@
+import "../yaml", common
+import math, strutils, stopwatch, terminal, algorithm
+
+from nimlets_yaml import objKind
+
+type
+    Level = tuple
+        kind: YamlNodeKind
+        len: int
+
+proc genString(maxLen: int): string =
+    let len = random(maxLen)
+    result = ""
+    for i in 1 .. len: result.add(cast[char](random(127 - 32) + 32))
+
+proc genBlockString(): string =
+    let lines = 5 + random(10)
+    let flow = random(2) == 0
+    result = ""
+    for i in 1 .. lines:
+        let lineLen = 32 + random(12)
+        for i in i .. lineLen: result.add(cast[char](random(127 - 33) + 33))
+        result.add(if flow: ' ' else: '\l')
+    result.add('\l')
+
+proc genKey(): string =
+    let genPossiblePlainKey = random(1.0) < 0.75
+    if genPossiblePlainKey:
+        result = ""
+        let len = random(24) + 1
+        for i in 1 .. len:
+            let c = random(26 + 26 + 10)
+            if c < 26: result.add(char(c + 65))
+            elif c < 52: result.add(char(c + 97 - 26))
+            else: result.add(char(c + 48 - 52)) 
+    else: result = genString(31) & char(random(26) + 65)
+
+proc genYamlString(size: int, maxStringLen: int,
+                   style: PresentationStyle): string =
+    ## Generates a random YAML string.
+    ## size is in KiB, mayStringLen in characters.
+    
+    randomize(size * maxStringLen * ord(style))
+    result = "{"
+    
+    let targetSize = size * 1024
+    var
+        target = newStringStream()
+        input = iterator(): YamlStreamEvent =
+            var
+                levels = newSeq[Level]()
+                curSize = 1
+            levels.add((kind: yMapping, len: 0))
+            yield startDocEvent()
+            yield startMapEvent()
+            
+            while levels.len > 0:
+                let
+                    objectCloseProbability =
+                        float(levels[levels.high].len + levels.high) * 0.025
+                    closeObject = random(1.0) <= objectCloseProbability
+        
+                if (closeObject and levels.len > 1) or curSize > targetSize:
+                    case levels[levels.high].kind
+                    of yMapping: yield endMapEvent()
+                    of ySequence: yield endSeqEvent()
+                    else: assert(false)
+                    curSize += 1
+                    discard levels.pop()
+                    continue
+        
+                levels[levels.high].len += 1
+                if levels[levels.high].kind == yMapping:
+                    let key = genKey()
+                    yield scalarEvent(key)
+    
+                let
+                    objectValueProbability =
+                        0.8 / float(levels.len * levels.len)
+                    generateObjectValue = random(1.0) <= objectValueProbability
+                    hasTag = random(2) == 0
+                var tag = yTagQuestionMark
+    
+                if generateObjectValue:
+                    let objectKind = if random(3) == 0: ySequence else: yMapping
+                    case objectKind
+                    of yMapping:
+                        if hasTag: tag = yTagMapping
+                        yield startMapEvent(tag)
+                    of ySequence:
+                        if hasTag: tag = yTagSequence
+                        yield startSeqEvent(tag)
+                    else: assert(false)
+                    curSize += 1
+                    levels.add((kind: objectKind, len: 0))
+                else:
+                    var s: string
+                    case random(11)
+                    of 0..4:
+                        s = genString(maxStringLen)
+                        if hasTag: tag = yTagString
+                    of 5:
+                        s = genBlockString()
+                    of 6..7:
+                        s = $random(32000)
+                        if hasTag: tag = yTagInteger
+                    of 8..9:
+                        s = $(random(424242.4242) - 212121.21)
+                        if hasTag: tag = yTagFloat
+                    of 10:
+                        case random(3)
+                        of 0:
+                            s = "true"
+                            if hasTag: tag = yTagBoolean
+                        of 1:
+                            s = "false"
+                            if hasTag: tag = yTagBoolean
+                        of 2:
+                            s = "null"
+                            if hasTag: tag = yTagNull
+                        else: discard
+                    else: discard
+        
+                    yield scalarEvent(s, tag)
+                    curSize += s.len
+            yield endDocEvent()
+    var yStream = initYamlStream(input)
+    present(yStream, target, initExtendedTagLibrary(),
+            defineOptions(style=style, outputVersion=ov1_1))
+    result = target.data
+    
+var
+    cYaml1k, cYaml10k, cYaml100k, cLibYaml1k, cLibYaml10k, cLibYaml100k: int64
+    yaml1k   = genYamlString(1, 32, psDefault)
+    yaml10k  = genYamlString(10, 32, psDefault)
+    yaml100k = genYamlString(100, 32, psDefault)
+    tagLib   = initExtendedTagLibrary()
+    parser = newYamlParser(tagLib)
+
+block:
+    multibench(cYaml1k, 100):
+        var s = newStringStream(yaml1k)
+        let res = loadDOM(s)
+        assert res.root.kind == yMapping
+
+block:
+    multibench(cYaml10k, 100):
+        var
+            s = newStringStream(yaml10k)
+        let res = loadDOM(s)
+        assert res.root.kind == yMapping
+
+block:
+    multibench(cYaml100k, 100):
+        var s = newStringStream(yaml100k)
+        let res = loadDOM(s)
+        assert res.root.kind == yMapping
+
+block:
+    multibench(cLibYaml1k, 100):
+        let res = nimlets_yaml.load(yaml1k)
+        assert res[0].objKind == nimlets_yaml.YamlObjKind.Map
+
+block:
+    multibench(cLibYaml10k, 100):
+        let res = nimlets_yaml.load(yaml10k)
+        assert res[0].objKind == nimlets_yaml.YamlObjKind.Map
+
+block:
+    multibench(cLibYaml100k, 100):
+        let res = nimlets_yaml.load(yaml100k)
+        assert res[0].objKind == nimlets_yaml.YamlObjKind.Map
+
+proc writeResult(caption: string, num: int64) =
+    styledWriteLine(stdout, resetStyle, caption, fgGreen, $num, resetStyle, "μs")
+
+setForegroundColor(fgWhite)
+
+writeStyled "Benchmark: Processing YAML input\n"
+writeStyled "================================\n"
+writeStyled "1k input\n--------\n"
+writeResult "NimYAML: ", cYaml1k div 1000
+writeResult "LibYAML: ", cLibYaml1k div 1000
+setForegroundColor(fgWhite)
+writeStyled "10k input\n---------\n"
+writeResult "NimYAML: ", cYaml10k div 1000
+writeResult "LibYAML: ", cLibYaml10k div 1000
+setForegroundColor(fgWhite)
+writeStyled "100k input\n----------\n"
+writeResult "NimYAML: ", cYaml100k div 1000
+writeResult "LibYAML: ", cLibYaml100k div 1000
\ No newline at end of file
diff --git a/config.nims b/config.nims
index 872da61..fe7eabb 100644
--- a/config.nims
+++ b/config.nims
@@ -32,7 +32,7 @@ task bench, "Benchmarking":
     --r
     --w:off
     --hints:off
-    setCommand "c", "bench/jsonBench"
+    setCommand "c", "bench/bench"
 
 task clean, "Remove all generated files":
     exec "rm -rf libyaml.* test/tests test/parsing test/lexing bench/json docout"