diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0afc283..9bc0849 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - More reliable start, no more flash of unindented text, or text that stays unindented (#107)
 - Pages with ANSI resets don't use the terminal's default text and background colors (#107)
 - ANSI documents don't leak color into the left margin (#107)
+- Rendering very long documents is now ~96% faster, excluding gemtext parsing (#107)
 
 
 ## [1.7.2] - 2020-12-21
diff --git a/NOTES.md b/NOTES.md
index 9c6d7ac..5af1b1e 100644
--- a/NOTES.md
+++ b/NOTES.md
@@ -4,9 +4,6 @@
 - URL for each tab should not be stored as a string - in the current code there's lots of reparsing the URL
 
 ## Upstream Bugs
-- Text background not reset on ANSI pages
-  - Filed [issue 25](https://gitlab.com/tslocum/cview/-/issues/25)
-  - Add some bold back into modal text after this is fixed
 - Bookmark keys aren't deleted, just set to `""`
   - Waiting on [this viper PR](https://github.com/spf13/viper/pull/519) to be merged
 - Help table cells aren't dynamically wrapped
diff --git a/display/bookmarks.go b/display/bookmarks.go
index 9a73b07..5062582 100644
--- a/display/bookmarks.go
+++ b/display/bookmarks.go
@@ -124,7 +124,7 @@ func Bookmarks(t *tab) {
 		bkmkPageRaw += fmt.Sprintf("=> %s %s\r\n", keys[i], m[keys[i]])
 	}
 	// Render and display
-	content, links := renderer.RenderGemini(bkmkPageRaw, textWidth(), leftMargin(), false)
+	content, links := renderer.RenderGemini(bkmkPageRaw, textWidth(), false)
 	page := structs.Page{
 		Raw:       bkmkPageRaw,
 		Content:   content,
diff --git a/display/display.go b/display/display.go
index 63e4cd0..34ea158 100644
--- a/display/display.go
+++ b/display/display.go
@@ -6,6 +6,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/gdamore/tcell/v2"
 	"github.com/makeworld-the-better-one/amfora/cache"
@@ -52,6 +53,9 @@ var layout = cview.NewFlex()
 var newTabPage structs.Page
 var versionPage structs.Page
 
+// Global mutex for changing the size of the left margin on all tabs.
+var reformatMu = sync.Mutex{}
+
 var App = cview.NewApplication()
 
 func Init(version, commit, builtBy string) {
@@ -59,7 +63,7 @@ func Init(version, commit, builtBy string) {
 		"# Amfora Version Info\n\nAmfora:   %s\nCommit:   %s\nBuilt by: %s",
 		version, commit, builtBy,
 	)
-	renderVersionContent, versionLinks := renderer.RenderGemini(versionContent, textWidth(), leftMargin(), false)
+	renderVersionContent, versionLinks := renderer.RenderGemini(versionContent, textWidth(), false)
 	versionPage = structs.Page{
 		Raw:       versionContent,
 		Content:   renderVersionContent,
@@ -78,10 +82,22 @@ func Init(version, commit, builtBy string) {
 
 		// Make sure the current tab content is reformatted when the terminal size changes
 		go func(t *tab) {
-			t.reformatMu.Lock() // Only one reformat job per tab
-			defer t.reformatMu.Unlock()
-			// Use the current tab, but don't affect other tabs if the user switches tabs
-			reformatPageAndSetView(t, t.page)
+			reformatMu.Lock()
+			// Lock the app to prevent screen updates until this is done, because calling
+			// browser.AddTab updates the display
+			for i := range tabs {
+				// Overwrite tabs with a new, differently sized, left margin
+				browser.AddTab(strconv.Itoa(i), makeTabLabel(strconv.Itoa(i+1)), makeContentLayout(tabs[i].view))
+				if tabs[i] == t {
+					// Reformat page ASAP, in the middle of loop
+					// TODO The per-tab mutext is unecessary if the global one is used
+					t.reformatMu.Lock() // Only one reformat job per tab
+					reformatPageAndSetView(t, t.page)
+					t.reformatMu.Unlock()
+				}
+			}
+			App.Draw()
+			reformatMu.Unlock()
 		}(tabs[curTab])
 	})
 
@@ -240,7 +256,7 @@ func Init(version, commit, builtBy string) {
 	// Render the default new tab content ONCE and store it for later
 	// This code is repeated in Reload()
 	newTabContent := getNewTabContent()
-	renderedNewTabContent, newTabLinks := renderer.RenderGemini(newTabContent, textWidth(), leftMargin(), false)
+	renderedNewTabContent, newTabLinks := renderer.RenderGemini(newTabContent, textWidth(), false)
 	newTabPage = structs.Page{
 		Raw:       newTabContent,
 		Content:   renderedNewTabContent,
@@ -436,7 +452,7 @@ func NewTab() {
 	tabs[curTab].addToHistory("about:newtab")
 	tabs[curTab].history.pos = 0 // Manually set as first page
 
-	browser.AddTab(strconv.Itoa(curTab), makeTabLabel(strconv.Itoa(curTab+1)), tabs[curTab].view)
+	browser.AddTab(strconv.Itoa(curTab), makeTabLabel(strconv.Itoa(curTab+1)), makeContentLayout(tabs[curTab].view))
 	browser.SetCurrentTab(strconv.Itoa(curTab))
 	App.SetFocus(tabs[curTab].view)
 
@@ -520,7 +536,7 @@ func Reload() {
 		// Re-render new tab, similar to Init()
 		newTabContent := getNewTabContent()
 		tmpTermW := termW
-		renderedNewTabContent, newTabLinks := renderer.RenderGemini(newTabContent, textWidth(), leftMargin(), false)
+		renderedNewTabContent, newTabLinks := renderer.RenderGemini(newTabContent, textWidth(), false)
 		newTabPage = structs.Page{
 			Raw:       newTabContent,
 			Content:   renderedNewTabContent,
diff --git a/display/file.go b/display/file.go
index 9349c86..a5ba3da 100644
--- a/display/file.go
+++ b/display/file.go
@@ -59,7 +59,7 @@ func handleFile(u string) (*structs.Page, bool) {
 		}
 
 		if mimetype == "text/gemini" {
-			rendered, links := renderer.RenderGemini(string(content), textWidth(), leftMargin(), false)
+			rendered, links := renderer.RenderGemini(string(content), textWidth(), false)
 			page = &structs.Page{
 				Mediatype: structs.TextGemini,
 				URL:       u,
@@ -73,7 +73,7 @@ func handleFile(u string) (*structs.Page, bool) {
 				Mediatype: structs.TextPlain,
 				URL:       u,
 				Raw:       string(content),
-				Content:   renderer.RenderPlainText(string(content), leftMargin()),
+				Content:   renderer.RenderPlainText(string(content)),
 				Links:     []string{},
 				Width:     termW,
 			}
@@ -107,7 +107,7 @@ func createDirectoryListing(u string) (*structs.Page, bool) {
 		content += fmt.Sprintf("=> %s%s %s%s\n", f.Name(), separator, f.Name(), separator)
 	}
 
-	rendered, links := renderer.RenderGemini(content, textWidth(), leftMargin(), false)
+	rendered, links := renderer.RenderGemini(content, textWidth(), false)
 	page = &structs.Page{
 		Mediatype: structs.TextGemini,
 		URL:       u,
diff --git a/display/handlers.go b/display/handlers.go
index e9234df..9ed4add 100644
--- a/display/handlers.go
+++ b/display/handlers.go
@@ -373,7 +373,7 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 	res.Body = rr.NewRestartReader(res.Body)
 
 	if renderer.CanDisplay(res) {
-		page, err := renderer.MakePage(u, res, textWidth(), leftMargin(), usingProxy)
+		page, err := renderer.MakePage(u, res, textWidth(), usingProxy)
 		// Rendering may have taken a while, make sure tab is still valid
 		if !isValidTab(t) {
 			return ret("", false)
diff --git a/display/private.go b/display/private.go
index 403e884..0bd7825 100644
--- a/display/private.go
+++ b/display/private.go
@@ -65,11 +65,11 @@ func reformatPage(p *structs.Page) {
 			strings.HasPrefix(p.URL, "file") {
 			proxied = false
 		}
-		rendered, _ = renderer.RenderGemini(p.Raw, textWidth(), leftMargin(), proxied)
+		rendered, _ = renderer.RenderGemini(p.Raw, textWidth(), proxied)
 	case structs.TextPlain:
-		rendered = renderer.RenderPlainText(p.Raw, leftMargin())
+		rendered = renderer.RenderPlainText(p.Raw)
 	case structs.TextAnsi:
-		rendered = renderer.RenderANSI(p.Raw, leftMargin())
+		rendered = renderer.RenderANSI(p.Raw)
 	default:
 		// Rendering this type is not implemented
 		return
@@ -89,6 +89,8 @@ func reformatPageAndSetView(t *tab, p *structs.Page) {
 	reformatPage(p)
 	t.view.SetText(p.Content)
 	t.applyScroll() // Go back to where you were, roughly
+
+	App.Draw()
 }
 
 // setPage displays a Page on the passed tab number.
diff --git a/display/subscriptions.go b/display/subscriptions.go
index 5e74127..d65c19e 100644
--- a/display/subscriptions.go
+++ b/display/subscriptions.go
@@ -149,7 +149,7 @@ func Subscriptions(t *tab, u string) string {
 		}
 	}
 
-	content, links := renderer.RenderGemini(rawPage, textWidth(), leftMargin(), false)
+	content, links := renderer.RenderGemini(rawPage, textWidth(), false)
 	page := structs.Page{
 		Raw:       rawPage,
 		Content:   content,
@@ -191,7 +191,7 @@ func ManageSubscriptions(t *tab, u string) {
 		)
 	}
 
-	content, links := renderer.RenderGemini(rawPage, textWidth(), leftMargin(), false)
+	content, links := renderer.RenderGemini(rawPage, textWidth(), false)
 	page := structs.Page{
 		Raw:       rawPage,
 		Content:   content,
diff --git a/display/util.go b/display/util.go
index fb8473b..ff0888b 100644
--- a/display/util.go
+++ b/display/util.go
@@ -13,6 +13,17 @@ import (
 
 // This file contains funcs that are small, self-contained utilities.
 
+// makeContentLayout returns a flex that contains the given TextView
+// along with the current correct left margin.
+func makeContentLayout(tv *cview.TextView) *cview.Flex {
+	// Create horizontal flex with the left margin as an empty space
+	flex := cview.NewFlex()
+	flex.SetDirection(cview.FlexColumn)
+	flex.AddItem(nil, leftMargin(), 0, false)
+	flex.AddItem(tv, 0, 1, true)
+	return flex
+}
+
 // makeTabLabel takes a string and adds spacing to it, making it
 // suitable for display as a tab label.
 func makeTabLabel(s string) string {
diff --git a/renderer/page.go b/renderer/page.go
index 0c43306..9c637bd 100644
--- a/renderer/page.go
+++ b/renderer/page.go
@@ -58,7 +58,7 @@ func CanDisplay(res *gemini.Response) bool {
 
 // MakePage creates a formatted, rendered Page from the given network response and params.
 // You must set the Page.Width value yourself.
-func MakePage(url string, res *gemini.Response, width, leftMargin int, proxied bool) (*structs.Page, error) {
+func MakePage(url string, res *gemini.Response, width int, proxied bool) (*structs.Page, error) {
 	if !CanDisplay(res) {
 		return nil, ErrCantDisplay
 	}
@@ -101,7 +101,7 @@ func MakePage(url string, res *gemini.Response, width, leftMargin int, proxied b
 	}
 
 	if mediatype == "text/gemini" {
-		rendered, links := RenderGemini(utfText, width, leftMargin, proxied)
+		rendered, links := RenderGemini(utfText, width, proxied)
 		return &structs.Page{
 			Mediatype:    structs.TextGemini,
 			RawMediatype: mediatype,
@@ -119,7 +119,7 @@ func MakePage(url string, res *gemini.Response, width, leftMargin int, proxied b
 				RawMediatype: mediatype,
 				URL:          url,
 				Raw:          utfText,
-				Content:      RenderANSI(utfText, leftMargin),
+				Content:      RenderANSI(utfText),
 				Links:        []string{},
 				MadeAt:       time.Now(),
 			}, nil
@@ -131,7 +131,7 @@ func MakePage(url string, res *gemini.Response, width, leftMargin int, proxied b
 			RawMediatype: mediatype,
 			URL:          url,
 			Raw:          utfText,
-			Content:      RenderPlainText(utfText, leftMargin),
+			Content:      RenderPlainText(utfText),
 			Links:        []string{},
 			MadeAt:       time.Now(),
 		}, nil
diff --git a/renderer/renderer.go b/renderer/renderer.go
index cd9d09b..9552835 100644
--- a/renderer/renderer.go
+++ b/renderer/renderer.go
@@ -21,7 +21,7 @@ var ansiRegex = regexp.MustCompile(`\x1b\[[0-9;]*m`)
 
 // RenderANSI renders plain text pages containing ANSI codes.
 // Practically, it is used for the text/x-ansi.
-func RenderANSI(s string, leftMargin int) string {
+func RenderANSI(s string) string {
 	s = cview.Escape(s)
 	if viper.GetBool("a-general.color") && viper.GetBool("a-general.ansi") {
 		s = cview.TranslateANSI(s)
@@ -33,24 +33,15 @@ func RenderANSI(s string, leftMargin int) string {
 	} else {
 		s = ansiRegex.ReplaceAllString(s, "")
 	}
-	var shifted string
-	lines := strings.Split(s, "\n")
-	for i := range lines {
-		shifted += fmt.Sprintf("[-:%s]", config.GetColorString("bg")) + strings.Repeat(" ", leftMargin) + lines[i] + "\n"
-	}
-	return shifted
+	return s
 }
 
 // RenderPlainText should be used to format plain text pages.
-func RenderPlainText(s string, leftMargin int) string {
-	var shifted string
-	lines := strings.Split(cview.Escape(s), "\n")
-	for i := range lines {
-		shifted += strings.Repeat(" ", leftMargin) +
-			"[" + config.GetColorString("regular_text") + "]" + lines[i] + "[-]" +
-			"\n"
-	}
-	return shifted
+func RenderPlainText(s string) string {
+	// It used to add a left margin, now this is done elsewhere.
+	// The function is kept for convenience and in case rendering
+	// is needed in the future.
+	return s
 }
 
 // wrapLine wraps a line to the provided width, and adds the provided prefix and suffix to each wrapped line.
@@ -283,7 +274,7 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 //
 // proxied is whether the request is through the gemini:// scheme.
 // If it's not a gemini:// page, set this to true.
-func RenderGemini(s string, width, leftMargin int, proxied bool) (string, []string) {
+func RenderGemini(s string, width int, proxied bool) (string, []string) {
 	s = cview.Escape(s)
 
 	lines := strings.Split(s, "\n")
@@ -357,13 +348,5 @@ func RenderGemini(s string, width, leftMargin int, proxied bool) (string, []stri
 		processRegular()
 	}
 
-	if leftMargin > 0 {
-		renLines := strings.Split(rendered, "\n")
-		for i := range renLines {
-			renLines[i] = strings.Repeat(" ", leftMargin) + renLines[i]
-		}
-		return strings.Join(renLines, "\n"), links
-	}
-
 	return rendered, links
 }