diff --git a/gallery_dl/extractor/batoto.py b/gallery_dl/extractor/batoto.py
index ac363052..65bc7c3d 100644
--- a/gallery_dl/extractor/batoto.py
+++ b/gallery_dl/extractor/batoto.py
@@ -8,10 +8,8 @@
 
 """Extract manga pages from http://bato.to/"""
 
-from .common import AsynchronousExtractor
-from .common import Message
-from .common import filename_from_url, unescape
-from urllib.parse import unquote
+from .common import AsynchronousExtractor, Message
+from .. import text
 import os.path
 import re
 
@@ -44,13 +42,13 @@ class BatotoExtractor(AsynchronousExtractor):
     def get_page_metadata(self, page_url):
         """Collect next url and metadata for one manga-page"""
         page = self.request(page_url).text
-        _    , pos = self.extract(page, 'selected="selected"', '')
-        title, pos = self.extract(page, ': ', '<', pos)
-        _    , pos = self.extract(page, 'selected="selected"', '', pos)
-        trans, pos = self.extract(page, '>', '<', pos)
-        _    , pos = self.extract(page, '<div id="full_image"', '', pos)
-        image, pos = self.extract(page, '<img src="', '"', pos)
-        url  , pos = self.extract(page, '<a href="', '"', pos)
+        _    , pos = text.extract(page, 'selected="selected"', '')
+        title, pos = text.extract(page, ': ', '<', pos)
+        _    , pos = text.extract(page, 'selected="selected"', '', pos)
+        trans, pos = text.extract(page, '>', '<', pos)
+        _    , pos = text.extract(page, '<div id="full_image"', '', pos)
+        image, pos = text.extract(page, '<img src="', '"', pos)
+        url  , pos = text.extract(page, '<a href="', '"', pos)
         mmatch = re.search(
             r"<title>(.+) - (?:vol (\d+) )?"
             r"ch (\d+)[^ ]+ Page (\d+) | Batoto!</title>",
@@ -60,18 +58,18 @@ class BatotoExtractor(AsynchronousExtractor):
             r"(.+) - ([^ ]+)",
             trans
         )
-        filename = unquote(filename_from_url(image))
+        filename = text.unquote(text.filename_from_url(image))
         name, ext = os.path.splitext(filename)
         return url, {
             "category": info["category"],
             "chapter-id": self.chapter_id,
-            "manga": unescape(mmatch.group(1)),
+            "manga": text.unescape(mmatch.group(1)),
             "volume": mmatch.group(2) or "",
             "chapter": mmatch.group(3),
             "page": mmatch.group(4),
             "group": tmatch.group(1),
             "language": tmatch.group(2),
-            "title": unescape(title),
+            "title": text.unescape(title),
             "image-url": image,
             "name": name,
             "extension": ext[1:],
diff --git a/gallery_dl/extractor/booru.py b/gallery_dl/extractor/booru.py
index 88600397..f72bc789 100644
--- a/gallery_dl/extractor/booru.py
+++ b/gallery_dl/extractor/booru.py
@@ -8,15 +8,13 @@
 
 """Base classes for extractors for danbooru and co"""
 
-from .common import SequentialExtractor
-from .common import Message
-from .common import filename_from_url
+from .common import SequentialExtractor, Message
+from .. import text
 import xml.etree.ElementTree as ET
 import json
 import os.path
 import urllib.parse
 
-
 class BooruExtractor(SequentialExtractor):
 
     api_url = ""
@@ -24,7 +22,7 @@ class BooruExtractor(SequentialExtractor):
     def __init__(self, match, config, info):
         SequentialExtractor.__init__(self, config)
         self.info = info
-        self.tags = urllib.parse.unquote(match.group(1))
+        self.tags = text.unquote(match.group(1))
         self.page = "page"
         self.params = {"tags": self.tags}
         self.headers = {}
@@ -58,8 +56,8 @@ class BooruExtractor(SequentialExtractor):
     def get_file_metadata(self, data):
         """Collect metadata for a downloadable file"""
         data["category"] = self.info["category"]
-        data["name"] = urllib.parse.unquote(
-            filename_from_url(self.get_file_url(data))
+        data["name"] = text.unquote(
+            text.filename_from_url(self.get_file_url(data))
         )
         data["extension"] = os.path.splitext(data["name"])[1][1:]
         return data
diff --git a/gallery_dl/extractor/chan.py b/gallery_dl/extractor/chan.py
index 2f943068..2d2b6fb4 100644
--- a/gallery_dl/extractor/chan.py
+++ b/gallery_dl/extractor/chan.py
@@ -9,6 +9,7 @@
 """Base classes for extractors for different Futaba Channel boards"""
 
 from .common import SequentialExtractor, Message
+from .. import text
 import re
 
 class ChanExtractor(SequentialExtractor):
@@ -44,5 +45,4 @@ class ChanExtractor(SequentialExtractor):
         """Return thread title from first post"""
         if "sub" in post:
             return post["sub"]
-        com = re.sub("<[^>]+?>", "", post["com"])
-        return " ".join(com.split())[:50]
+        return text.remove_html(post["com"])[:50]
diff --git a/gallery_dl/extractor/common.py b/gallery_dl/extractor/common.py
index cb8e91ca..b364d870 100644
--- a/gallery_dl/extractor/common.py
+++ b/gallery_dl/extractor/common.py
@@ -44,24 +44,6 @@ class Extractor():
             "Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Firefox/24.0"
         )
 
-    @staticmethod
-    def extract(txt, begin, end, pos=0):
-        try:
-            first = txt.index(begin, pos) + len(begin)
-            last = txt.index(end, first)
-            return txt[first:last], last+len(end)
-        except ValueError:
-            return None, pos
-
-    @staticmethod
-    def extract_all(txt, begin, end, pos=0):
-        try:
-            first = txt.index(begin, pos)
-            last = txt.index(end, first + len(begin)) + len(end)
-            return txt[first:last], last
-        except ValueError:
-            return None, pos
-
 
 class SequentialExtractor(Extractor):
 
@@ -123,9 +105,3 @@ def safe_request(session, url, method="GET", *args, **kwargs):
 
         # everything ok -- proceed to download
         return r
-
-def filename_from_url(url):
-    pos = url.rfind("/")
-    return url[pos+1:]
-
-unescape = html.parser.HTMLParser().unescape
diff --git a/gallery_dl/extractor/imagebam.py b/gallery_dl/extractor/imagebam.py
index f8886a7a..c89721f2 100644
--- a/gallery_dl/extractor/imagebam.py
+++ b/gallery_dl/extractor/imagebam.py
@@ -8,9 +8,8 @@
 
 """Extract images from galleries at http://www.imagebam.com/"""
 
-from .common import AsynchronousExtractor
-from .common import Message
-from .common import filename_from_url
+from .common import AsynchronousExtractor, Message
+from .. import text
 
 info = {
     "category": "imagebam",
@@ -42,28 +41,28 @@ class ImagebamExtractor(AsynchronousExtractor):
         done = False
         while not done:
             # get current page
-            text = self.request(self.url_base + next_url).text
+            page = self.request(self.url_base + next_url).text
 
             # get url for next page
-            next_url, pos = self.extract(text, "<a class='buttonblue' href='", "'")
+            next_url, pos = text.extract(page, "<a class='buttonblue' href='", "'")
 
             # if the following text isn't "><span>next image" we are done
-            if not text.startswith("><span>next image", pos):
+            if not page.startswith("><span>next image", pos):
                 done = True
 
             # get image url
-            img_url, pos = self.extract(text, 'onclick="scale(this);" src="', '"', pos)
+            img_url, pos = text.extract(page, 'onclick="scale(this);" src="', '"', pos)
 
             yield Message.Url, img_url, self.get_file_metadata(img_url)
 
     def get_job_metadata(self):
         """Collect metadata for extractor-job"""
         gallery_key = self.match.group(2)
-        text = self.request(self.url_base + "/gallery/" + gallery_key).text
-        _    , pos = self.extract(text, "<img src='/img/icons/photos.png'", "")
-        title, pos = self.extract(text, "'> ", " <", pos)
-        count, pos = self.extract(text, "'>", " images", pos)
-        url  , pos = self.extract(text, "<a href='http://www.imagebam.com", "'", pos)
+        page = self.request(self.url_base + "/gallery/" + gallery_key).text
+        _    , pos = text.extract(page, "<img src='/img/icons/photos.png'", "")
+        title, pos = text.extract(page, "'> ", " <", pos)
+        count, pos = text.extract(page, "'>", " images", pos)
+        url  , pos = text.extract(page, "<a href='http://www.imagebam.com", "'", pos)
         return {
             "category": info["category"],
             "key": gallery_key,
@@ -77,5 +76,5 @@ class ImagebamExtractor(AsynchronousExtractor):
         self.num += 1
         data = self.metadata.copy()
         data["num"] = self.num
-        data["name"] = filename_from_url(url)
+        data["name"] = text.filename_from_url(url)
         return data
diff --git a/gallery_dl/extractor/imgbox.py b/gallery_dl/extractor/imgbox.py
index 50412eb7..3de51f27 100644
--- a/gallery_dl/extractor/imgbox.py
+++ b/gallery_dl/extractor/imgbox.py
@@ -9,6 +9,7 @@
 """Extract images from galleries at http://imgbox.com/"""
 
 from .common import AsynchronousExtractor, Message
+from .. import text
 import re
 
 info = {
@@ -36,8 +37,8 @@ class ImgboxExtractor(AsynchronousExtractor):
         yield Message.Version, 1
         yield Message.Directory, self.metadata
         for match in re.finditer(r'<a href="([^"]+)"><img alt="', page):
-            text = self.request(self.url_base + match.group(1)).text
-            yield Message.Url, self.get_file_url(text), self.get_file_metadata(text)
+            imgpage = self.request(self.url_base + match.group(1)).text
+            yield Message.Url, self.get_file_url(imgpage), self.get_file_metadata(imgpage)
 
     def get_job_metadata(self, page):
         """Collect metadata for extractor-job"""
@@ -51,16 +52,16 @@ class ImgboxExtractor(AsynchronousExtractor):
             "count": match.group(4),
         }
 
-    def get_file_metadata(self, text):
+    def get_file_metadata(self, page):
         """Collect metadata for a downloadable file"""
         data = self.metadata.copy()
-        data["num"]      , pos = self.extract(text, '</a> &nbsp; ', ' of ')
-        data["image-key"], pos = self.extract(text, '/i.imgbox.com/', '?download', pos)
-        data["name"]     , pos = self.extract(text, ' title="', '"', pos)
+        data["num"]      , pos = text.extract(page, '</a> &nbsp; ', ' of ')
+        data["image-key"], pos = text.extract(page, '/i.imgbox.com/', '?download', pos)
+        data["name"]     , pos = text.extract(page, ' title="', '"', pos)
         return data
 
-    def get_file_url(self, text):
+    def get_file_url(self, page):
         """Extract download-url"""
         base = "http://i.imgbox.com/"
-        path, _ = self.extract(text, base, '"')
+        path, _ = text.extract(page, base, '"')
         return base + path
diff --git a/gallery_dl/extractor/imgchili.py b/gallery_dl/extractor/imgchili.py
index 40932912..9e591e57 100644
--- a/gallery_dl/extractor/imgchili.py
+++ b/gallery_dl/extractor/imgchili.py
@@ -8,9 +8,8 @@
 
 """Extract images from albums at http://imgchili.net/"""
 
-from .common import SequentialExtractor
-from .common import Message
-from .common import filename_from_url
+from .common import SequentialExtractor, Message
+from .. import text
 import re
 
 info = {
@@ -42,7 +41,7 @@ class ImgchiliExtractor(SequentialExtractor):
 
     def get_job_metadata(self, page):
         """Collect metadata for extractor-job"""
-        title = self.extract(page, "<h1>", "</h1>")[0]
+        title = text.extract(page, "<h1>", "</h1>")[0]
         return {
             "category": info["category"],
             "title": title,
diff --git a/gallery_dl/extractor/mangareader.py b/gallery_dl/extractor/mangareader.py
index 62575308..60ed473a 100644
--- a/gallery_dl/extractor/mangareader.py
+++ b/gallery_dl/extractor/mangareader.py
@@ -8,10 +8,8 @@
 
 """Extract manga pages from http://www.mangareader.net/"""
 
-from .common import AsynchronousExtractor
-from .common import Message
-from .common import unescape, filename_from_url
-from urllib.parse import unquote
+from .common import AsynchronousExtractor, Message
+from .. import text
 import os.path
 import re
 
@@ -47,7 +45,7 @@ class MangaReaderExtractor(AsynchronousExtractor):
     def get_page_metadata(self, page_url):
         """Collect next url, image-url and metadata for one manga-page"""
         page = self.request(page_url).text
-        extr = self.extract
+        extr = text.extract
         width = None
         descr, pos = extr(page, '<meta name="description" content="', '"')
         test , pos = extr(page, "document['pu']", '', pos)
@@ -62,13 +60,13 @@ class MangaReaderExtractor(AsynchronousExtractor):
             width , pos = extr(page, '<img id="img" width="', '"', pos)
             height, pos = extr(page, ' height="', '"', pos)
         image, pos = extr(page, ' src="', '"', pos)
-        filename = unquote(filename_from_url(image))
+        filename = text.unquote(text.filename_from_url(image))
         name, ext = os.path.splitext(filename)
         match = re.match(r"(.*) (\d+) - Read \1 \2 Manga Scans Page (\d+)", descr)
 
         return self.url_base + url, image, {
             "category": info["category"],
-            "manga": unescape(match.group(1)),
+            "manga": text.unescape(match.group(1)),
             "chapter": match.group(2),
             "page": match.group(3),
             "width": width,
diff --git a/gallery_dl/extractor/nijie.py b/gallery_dl/extractor/nijie.py
index 3a9e19df..afeefd60 100644
--- a/gallery_dl/extractor/nijie.py
+++ b/gallery_dl/extractor/nijie.py
@@ -8,9 +8,8 @@
 
 """Extract images from https://nijie.info/"""
 
-from .common import AsynchronousExtractor
-from .common import Message
-from .common import filename_from_url
+from .common import AsynchronousExtractor, Message
+from ..text  import filename_from_url
 import re
 
 info = {
@@ -56,6 +55,7 @@ class NijieExtractor(AsynchronousExtractor):
         }
 
     def get_image_ids(self):
+        """Collect all image-ids for a specific artist"""
         text = self.request(self.artist_url).text
         regex = r'<a href="/view\.php\?id=(\d+)"'
         return [m.group(1) for m in re.finditer(regex, text)]
diff --git a/gallery_dl/extractor/pixiv.py b/gallery_dl/extractor/pixiv.py
index 71674899..8b28af57 100644
--- a/gallery_dl/extractor/pixiv.py
+++ b/gallery_dl/extractor/pixiv.py
@@ -8,8 +8,8 @@
 
 """Extract images and ugoira from http://www.pixiv.net/"""
 
-from .common import SequentialExtractor
-from .common import Message
+from .common import SequentialExtractor, Message
+from .. import text
 import re
 import json
 
@@ -84,9 +84,9 @@ class PixivExtractor(SequentialExtractor):
 
     def get_works(self):
         """Yield all work-items for a pixiv-member"""
-        page = 1
+        pagenum = 1
         while True:
-            data = self.api.user_works(self.artist_id, page)
+            data = self.api.user_works(self.artist_id, pagenum)
             for work in data["response"]:
                 url = work["image_urls"]["large"]
                 work["num"] = ""
@@ -96,17 +96,17 @@ class PixivExtractor(SequentialExtractor):
             pinfo = data["pagination"]
             if pinfo["current"] == pinfo["pages"]:
                 return
-            page = pinfo["next"]
+            pagenum = pinfo["next"]
 
     def parse_ugoira(self, data):
         """Parse ugoira data"""
         # get illust page
-        text = self.request(
+        page = self.request(
             self.illust_url, params={"illust_id": data["id"]},
         ).text
 
         # parse page
-        frames, _ = self.extract(text, ',"frames":[', ']')
+        frames, _ = text.extract(page, ',"frames":[', ']')
 
         # build url
         url = re.sub(
diff --git a/gallery_dl/extractor/redhawkscans.py b/gallery_dl/extractor/redhawkscans.py
index c9fe0ca7..5c9593b2 100644
--- a/gallery_dl/extractor/redhawkscans.py
+++ b/gallery_dl/extractor/redhawkscans.py
@@ -8,9 +8,8 @@
 
 """Extract manga pages from http://manga.redhawkscans.com/"""
 
-from .common import SequentialExtractor
-from .common import Message
-from .common import unescape
+from .common import SequentialExtractor, Message
+from .. import text
 import os.path
 import json
 import re
@@ -50,16 +49,16 @@ class RedHawkScansExtractor(SequentialExtractor):
         response = self.request(self.url_base + self.part)
         response.encoding = "utf-8"
         page = response.text
-        _        , pos = self.extract(page, '<h1 class="tbtitle dnone">', '')
-        manga    , pos = self.extract(page, 'title="', '"', pos)
-        chapter  , pos = self.extract(page, '">', '</a>', pos)
-        json_data, pos = self.extract(page, 'var pages = ', ';\r\n', pos)
+        _        , pos = text.extract(page, '<h1 class="tbtitle dnone">', '')
+        manga    , pos = text.extract(page, 'title="', '"', pos)
+        chapter  , pos = text.extract(page, '">', '</a>', pos)
+        json_data, pos = text.extract(page, 'var pages = ', ';\r\n', pos)
         match = re.match(r"(Chapter (\d+)([^:+]*)(?:: (.*))?|[^:]+)", chapter)
         return {
             "category": info["category"],
-            "manga": unescape(manga),
+            "manga": text.unescape(manga),
             "chapter": match.group(2) or match.group(1),
             "chapter-minor": match.group(3) or "",
             "language": "English",
-            "title": unescape(match.group(4) or ""),
+            "title": text.unescape(match.group(4) or ""),
         }, json.loads(json_data)