diff --git a/src/main/kotlin/space/kscience/snark/HtmlData.kt b/src/main/kotlin/space/kscience/snark/HtmlData.kt
index fd836b0..ad44fea 100644
--- a/src/main/kotlin/space/kscience/snark/HtmlData.kt
+++ b/src/main/kotlin/space/kscience/snark/HtmlData.kt
@@ -13,22 +13,18 @@ import space.kscience.dataforge.meta.string
 
 
 //TODO replace by VisionForge type
-typealias HtmlFragment = TagConsumer<*>.() -> Unit
+typealias HtmlFragment = context(PageBuilder, TagConsumer<*>) () -> Unit
 
 typealias HtmlData = Data<HtmlFragment>
 
-fun HtmlData(meta: Meta, content: TagConsumer<*>.() -> Unit): HtmlData = Data(content, meta)
+fun HtmlData(meta: Meta, content: context(PageBuilder, TagConsumer<*>) () -> Unit): HtmlData =
+    Data(content, meta)
 
-val HtmlData.id: String get() = meta["id"]?.string ?: "block[${hashCode()}]"
-val HtmlData.language: String? get() = meta["language"].string?.lowercase()
+internal val HtmlData.id: String get() = meta["id"]?.string ?: "block[${hashCode()}]"
+internal val HtmlData.language: String? get() = meta["language"].string?.lowercase()
 
-val HtmlData.order: Int? get() = meta["order"]?.int
-
-fun TagConsumer<*>.htmlData(data: HtmlData) = runBlocking(Dispatchers.IO) {
-    data.await().invoke(this@htmlData)
-}
-
-fun FlowContent.htmlData(data: HtmlData) = runBlocking(Dispatchers.IO) {
-    data.await().invoke(consumer)
-}
+internal val HtmlData.order: Int? get() = meta["order"]?.int
 
+context(PageBuilder) fun FlowContent.htmlData(data: HtmlData) = runBlocking(Dispatchers.IO) {
+    data.await().invoke(this@PageBuilder, consumer)
+}
\ No newline at end of file
diff --git a/src/main/kotlin/space/kscience/snark/SiteLayout.kt b/src/main/kotlin/space/kscience/snark/SiteLayout.kt
index 9062a78..f86469d 100644
--- a/src/main/kotlin/space/kscience/snark/SiteLayout.kt
+++ b/src/main/kotlin/space/kscience/snark/SiteLayout.kt
@@ -1,9 +1,10 @@
 package space.kscience.snark
 
-import kotlinx.coroutines.runBlocking
+import kotlinx.html.body
+import kotlinx.html.head
+import kotlinx.html.title
 import space.kscience.dataforge.data.Data
 import space.kscience.dataforge.data.DataTreeItem
-import space.kscience.dataforge.data.await
 import space.kscience.dataforge.data.getItem
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.get
@@ -117,12 +118,16 @@ fun interface SiteLayout {
         const val ASSETS_KEY = "assets"
         val INDEX_PAGE_TOKEN = NameToken("index")
 
-        val defaultDataRenderer: SiteBuilder.(Data<*>) -> Unit = { data ->
+        val defaultDataRenderer: SiteBuilder.(Data<*>) -> Unit = { data: Data<*> ->
             if (data.type == typeOf<HtmlData>()) {
                 page {
-                    @Suppress("UNCHECKED_CAST")
-                    val pageFragment: HtmlFragment = runBlocking { data.await() as HtmlFragment }
-                    pageFragment.invoke(consumer)
+                    head {
+                        title = data.meta["title"].string ?: "Untitled page"
+                    }
+                    body {
+                        @Suppress("UNCHECKED_CAST")
+                        htmlData(data as HtmlData)
+                    }
                 }
             }
         }
diff --git a/src/main/kotlin/space/kscience/snark/SnarkPlugin.kt b/src/main/kotlin/space/kscience/snark/SnarkPlugin.kt
index ee5c680..41df20d 100644
--- a/src/main/kotlin/space/kscience/snark/SnarkPlugin.kt
+++ b/src/main/kotlin/space/kscience/snark/SnarkPlugin.kt
@@ -1,12 +1,14 @@
 package space.kscience.snark
 
 import io.ktor.util.extension
+import io.ktor.utils.io.core.Input
 import io.ktor.utils.io.core.readBytes
 import space.kscience.dataforge.context.*
 import space.kscience.dataforge.data.DataTree
 import space.kscience.dataforge.io.IOReader
 import space.kscience.dataforge.io.JsonMetaFormat
 import space.kscience.dataforge.io.asBinary
+import space.kscience.dataforge.io.readWith
 import space.kscience.dataforge.io.yaml.YamlMetaFormat
 import space.kscience.dataforge.io.yaml.YamlPlugin
 import space.kscience.dataforge.meta.Meta
@@ -27,13 +29,19 @@ import kotlin.reflect.typeOf
  * A parser of binary content including priority flag and file extensions
  */
 @Type(SnarkParser.TYPE)
-interface SnarkParser<out R : Any> : IOReader<R> {
+interface SnarkParser<out R> {
+    val type: KType
+
     val fileExtensions: Set<String>
 
     val priority: Int get() = DEFAULT_PRIORITY
 
-    suspend fun parse(bytes: ByteArray, meta: Meta): R = bytes.asBinary().read {
-        readObject(this)
+    fun parse(snark: SnarkPlugin, meta: Meta, bytes: ByteArray): R
+
+    fun reader(snark: SnarkPlugin, meta: Meta) = object : IOReader<R> {
+        override val type: KType get() = this@SnarkParser.type
+
+        override fun readObject(input: Input): R = parse(snark, meta, input.readBytes())
     }
 
     companion object {
@@ -47,7 +55,9 @@ internal class SnarkParserWrapper<R : Any>(
     val reader: IOReader<R>,
     override val type: KType,
     override val fileExtensions: Set<String>,
-) : SnarkParser<R>, IOReader<R> by reader
+) : SnarkParser<R> {
+    override fun parse(snark: SnarkPlugin, meta: Meta, bytes: ByteArray): R = bytes.asBinary().readWith(reader)
+}
 
 /**
  * Create a generic parser from reader
@@ -65,25 +75,25 @@ class SnarkPlugin : AbstractPlugin() {
 
     override val tag: PluginTag get() = Companion.tag
 
-    private val parsers: Map<Name, SnarkParser<*>> by lazy {
+    private val parsers: Map<Name, SnarkParser<Any>> by lazy {
         context.gather(SnarkParser.TYPE, true)
     }
 
     fun readDirectory(path: Path): DataTree<Any> = io.readDataDirectory(path) { dataPath, meta ->
         val fileExtension = meta[FileData.META_FILE_EXTENSION_KEY].string ?: dataPath.extension
-        val parser: SnarkParser<*>? = parsers.values.filter { parser ->
+        val parser: SnarkParser<Any> = parsers.values.filter { parser ->
             fileExtension in parser.fileExtensions
         }.maxByOrNull {
             it.priority
+        } ?: run {
+            logger.warn { "The parser is not found for file $dataPath with meta $meta" }
+            byteArraySnarkParser
         }
 
-        parser ?: run {
-            logger.warn { "The parser is not found for file $dataPath with meta $meta" }
-            byteArrayIOReader
-        }
+        parser.reader(this, meta)
     }
 
-    fun layout(meta: Meta): SiteLayout = when(meta[SiteLayout.LAYOUT_KEY]){
+    fun layout(meta: Meta): SiteLayout = when (meta[SiteLayout.LAYOUT_KEY]) {
         else -> DefaultSiteLayout
     }
 
@@ -95,7 +105,7 @@ class SnarkPlugin : AbstractPlugin() {
             "yaml".asName() to SnarkParser(YamlMetaFormat, "yaml", "yml"),
             "png".asName() to SnarkParser(ImageIOReader, "png"),
             "jpg".asName() to SnarkParser(ImageIOReader, "jpg", "jpeg"),
-            "gif".asName() to SnarkParser(ImageIOReader, "jpg", "jpeg"),
+            "gif".asName() to SnarkParser(ImageIOReader, "gif"),
         )
         else -> super.content(target)
     }
@@ -109,5 +119,7 @@ class SnarkPlugin : AbstractPlugin() {
         private val byteArrayIOReader = IOReader {
             readBytes()
         }
+
+        private val byteArraySnarkParser = SnarkParser(byteArrayIOReader)
     }
 }
\ No newline at end of file
diff --git a/src/main/kotlin/space/kscience/snark/parsers.kt b/src/main/kotlin/space/kscience/snark/parsers.kt
index 05ac768..eb0658d 100644
--- a/src/main/kotlin/space/kscience/snark/parsers.kt
+++ b/src/main/kotlin/space/kscience/snark/parsers.kt
@@ -8,33 +8,41 @@ import org.intellij.markdown.flavours.commonmark.CommonMarkFlavourDescriptor
 import org.intellij.markdown.html.HtmlGenerator
 import org.intellij.markdown.parser.MarkdownParser
 import space.kscience.dataforge.io.IOReader
+import space.kscience.dataforge.meta.Meta
 import java.awt.image.BufferedImage
 import javax.imageio.ImageIO
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
-internal object SnarkHtmlParser : SnarkParser<HtmlFragment> {
+abstract class SnarkTextParser<R> : SnarkParser<R> {
+    abstract fun parseText(text: String, meta: Meta): R
+
+    override fun parse(snark: SnarkPlugin, meta: Meta, bytes: ByteArray): R =
+        parseText(bytes.decodeToString(), meta)
+}
+
+
+internal object SnarkHtmlParser : SnarkTextParser<HtmlFragment>() {
     override val fileExtensions: Set<String> = setOf("html")
     override val type: KType = typeOf<HtmlFragment>()
 
-    override fun readObject(input: Input): HtmlFragment = {
+    override fun parseText(text: String, meta: Meta): HtmlFragment = {
         div {
-            unsafe { +input.readText() }
+            unsafe { +text }
         }
     }
 }
 
-internal object SnarkMarkdownParser : SnarkParser<HtmlFragment> {
+internal object SnarkMarkdownParser : SnarkTextParser<HtmlFragment>() {
     override val fileExtensions: Set<String> = setOf("markdown", "mdown", "mkdn", "mkd", "md")
     override val type: KType = typeOf<HtmlFragment>()
 
     private val markdownFlavor = CommonMarkFlavourDescriptor()
     private val markdownParser = MarkdownParser(markdownFlavor)
 
-    override fun readObject(input: Input): HtmlFragment {
-        val src = input.readText()
-        val parsedTree = markdownParser.buildMarkdownTreeFromString(src)
-        val htmlString = HtmlGenerator(src, parsedTree, markdownFlavor).generateHtml()
+    override fun parseText(text: String, meta: Meta): HtmlFragment {
+        val parsedTree = markdownParser.buildMarkdownTreeFromString(text)
+        val htmlString = HtmlGenerator(text, parsedTree, markdownFlavor).generateHtml()
 
         return {
             div {