diff --git a/lua/import-cost.lua b/lua/import-cost.lua
index 89730f4..8c7dd6a 100644
--- a/lua/import-cost.lua
+++ b/lua/import-cost.lua
@@ -10,7 +10,7 @@ local function au(events, cb)
     vim.api.nvim_create_autocmd(events, {
         callback = function(opts)
             if is_ic_buf(opts.buf) then
-                cb(opts)
+                cb(opts.buf)
             end
         end,
         group = M.aug_id,
@@ -25,8 +25,8 @@ M.config = {
         'typescriptreact',
     },
     format = {
-        byte_format = '%.2f b',
-        kb_format = '%.2f kb',
+        byte_format = '%.1fb',
+        kb_format = '%.1fk',
         virtual_text = '%s (gzipped: %s)',
     },
     highlight = 'Comment',
@@ -52,12 +52,21 @@ M.setup = function(user_config)
 
     local extmark = require 'import-cost.extmark'
 
-    au({ 'BufEnter', 'BufWritePost' }, function(opts)
-        extmark.set_missing_extmarks(opts.buf)
+    au('BufEnter', function(bufnr)
+        extmark.set_extmarks(bufnr)
     end)
 
-    au('TextChanged', function(opts)
-        extmark.update_extmarks(opts.buf)
+    au('InsertEnter', function(bufnr)
+        extmark.delete_extmarks(bufnr)
+    end)
+
+    au('InsertLeave', function(bufnr)
+        extmark.set_extmarks(bufnr)
+    end)
+
+    au('TextChanged', function(bufnr)
+        extmark.delete_extmarks(bufnr)
+        extmark.set_extmarks(bufnr)
     end)
 end
 
diff --git a/lua/import-cost/extmark.lua b/lua/import-cost/extmark.lua
index 28bce0d..48388f7 100644
--- a/lua/import-cost/extmark.lua
+++ b/lua/import-cost/extmark.lua
@@ -3,22 +3,30 @@ local M = {}
 local ic, job, util =
     require 'import-cost', require 'import-cost.job', require 'import-cost.util'
 
-local visible_strings = {}
+local cache = {}
 
-local function update_visible_strings(bufnr, data, extmark_id)
-    if not visible_strings[bufnr] then
-        visible_strings[bufnr] = {}
+local function update_cache(bufnr, data, extmark_id)
+    if not cache[bufnr] then
+        cache[bufnr] = {}
     end
 
-    visible_strings[bufnr][data.string] = data
-    visible_strings[bufnr][data.string].extmark_id = extmark_id
+    cache[bufnr][data.string] = data
+    cache[bufnr][data.string].extmark_id = extmark_id
 end
 
-local function string_visible(bufnr, string)
-    return visible_strings[bufnr] and visible_strings[bufnr][string]
+local function set_extmark(bufnr, data)
+    local string = util.normalize_string(data.string)
+
+    if cache[bufnr] and cache[bufnr][string] then
+        return
+    end
+
+    data.string = string
+    local extmark_id = job.render_extmark(bufnr, data)
+    update_cache(bufnr, data, extmark_id)
 end
 
-function M.set_missing_extmarks(bufnr)
+function M.set_extmarks(bufnr)
     local path = vim.api.nvim_buf_get_name(bufnr)
     local filetype = vim.api.nvim_buf_get_option(bufnr, 'filetype')
 
@@ -35,16 +43,8 @@ function M.set_missing_extmarks(bufnr)
             for _, chunk in ipairs(chunks) do
                 local data = util.parse_data(chunk)
 
-                if util.is_ok(data) then
-                    local string = util.normalize_string(data.string)
-
-                    if not string_visible(bufnr, string) then
-                        data.string = string
-
-                        local extmark_id = job.set_extmark(bufnr, data)
-
-                        update_visible_strings(bufnr, data, extmark_id)
-                    end
+                if data and data.size then
+                    set_extmark(bufnr, data)
                 end
             end
         end,
@@ -55,49 +55,30 @@ function M.set_missing_extmarks(bufnr)
 end
 
 function M.clear_extmarks(bufnr)
-    if visible_strings[bufnr] then
-        visible_strings[bufnr] = nil
+    if cache[bufnr] then
+        cache[bufnr] = nil
     end
 
     vim.api.nvim_buf_clear_namespace(bufnr, ic.ns_id, 0, -1)
 end
 
-function M.update_extmarks(bufnr)
-    local buffer_strings = M.move_existing_extmarks(bufnr)
-    M.delete_remaining_extmarks(bufnr, buffer_strings)
-    M.set_missing_extmarks(bufnr)
-end
-
-function M.move_existing_extmarks(bufnr)
-    local buffer_strings = {}
-
-    for nr, raw_string in ipairs(vim.api.nvim_buf_get_lines(bufnr, 0, -1, true)) do
-        if util.is_import_string(raw_string) then
-            local string = util.normalize_string(raw_string)
-            local data = visible_strings[bufnr][string]
-
-            buffer_strings[string] = true
-
-            if data and data.string == string then
-                if data.line ~= nr then
-                    data.line = nr
-
-                    job.set_extmark(bufnr, data, data.extmark_id)
-                end
-            end
-        end
+function M.delete_extmarks(bufnr)
+    if not cache[bufnr] then
+        return
     end
 
-    return buffer_strings
-end
-
-function M.delete_remaining_extmarks(bufnr, buffer_strings)
-    for string, data in pairs(visible_strings[bufnr]) do
-        if not buffer_strings[string] then
+    for string, data in pairs(cache[bufnr]) do
+        if
+            string
+            == util.normalize_string(vim.fn.getbufoneline(bufnr, data.line))
+        then
+            goto continue
+        else
             vim.api.nvim_buf_del_extmark(bufnr, ic.ns_id, data.extmark_id)
-
-            visible_strings[bufnr][string] = nil
+            cache[bufnr][string] = nil
         end
+
+        ::continue::
     end
 end
 
diff --git a/lua/import-cost/job.lua b/lua/import-cost/job.lua
index e4fb2d5..c58cddc 100644
--- a/lua/import-cost/job.lua
+++ b/lua/import-cost/job.lua
@@ -13,7 +13,7 @@ local format_bytes = function(bytes)
     return string.format(format.kb_format, 0.0009765625 * bytes)
 end
 
-function M.set_extmark(bufnr, data, extmark_id)
+function M.render_extmark(bufnr, data, extmark_id)
     local line, size, gzip =
         data.line - 1, format_bytes(data.size), format_bytes(data.gzip)
 
diff --git a/lua/import-cost/util.lua b/lua/import-cost/util.lua
index 91a9f76..0acf2be 100644
--- a/lua/import-cost/util.lua
+++ b/lua/import-cost/util.lua
@@ -32,8 +32,4 @@ function M.parse_data(chunk)
     return json.data
 end
 
-function M.is_ok(data)
-    return data and data.size
-end
-
 return M