diff --git a/.clang-tidy b/.clang-tidy
index cb2c5202..c4c73b3d 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -23,7 +23,8 @@ clang-analyzer-*,
 -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
 -readability-named-parameter,
 -cert-env33-c,
--modernize-concat-nested-namespaces
+-modernize-concat-nested-namespaces,
+-cppcoreguidelines-owning-memory
 '
 
 
diff --git a/include/spdlog/cfg/helpers.h b/include/spdlog/cfg/helpers.h
index f928d91d..c9acf7dd 100644
--- a/include/spdlog/cfg/helpers.h
+++ b/include/spdlog/cfg/helpers.h
@@ -19,7 +19,7 @@ namespace helpers {
 // turn off all logging except for logger1: "off,logger1=debug"
 // turn off all logging except for logger1 and logger2: "off,logger1=debug,logger2=info"
 //
-SPDLOG_API void load_levels(const std::string &txt);
+SPDLOG_API void load_levels(const std::string &input);
 }  // namespace helpers
 }  // namespace cfg
 }  // namespace spdlog
diff --git a/include/spdlog/details/file_helper.h b/include/spdlog/details/file_helper.h
index c267129c..1e5ca4c6 100644
--- a/include/spdlog/details/file_helper.h
+++ b/include/spdlog/details/file_helper.h
@@ -17,7 +17,7 @@ namespace details {
 class SPDLOG_API file_helper {
 public:
     file_helper() = default;
-    explicit file_helper(const file_event_handlers &event_handlers);
+    explicit file_helper(file_event_handlers event_handlers);
 
     file_helper(const file_helper &) = delete;
     file_helper &operator=(const file_helper &) = delete;
diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index b9ed7e1f..36f8df9a 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -184,11 +184,11 @@ protected:
     // common implementation for after templated public api has been resolved to format string and
     // args
     template <typename... Args>
-    void log_with_format_(source_loc loc, level lvl, const format_string_t<Args...> &fmt, Args &&...args) {
+    void log_with_format_(source_loc loc, const level lvl, const format_string_t<Args...> &format_string, Args &&...args) {
         assert(should_log(lvl));
         SPDLOG_TRY {
             memory_buf_t buf;
-            fmt::vformat_to(std::back_inserter(buf), fmt, fmt::make_format_args(args...));
+            fmt::vformat_to(std::back_inserter(buf), format_string, fmt::make_format_args(args...));
             sink_it_(details::log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size())));
         }
         SPDLOG_LOGGER_CATCH(loc)
diff --git a/src/common.cpp b/src/common.cpp
index c847eafd..fd046237 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -9,7 +9,7 @@
 namespace spdlog {
 
 spdlog::level level_from_str(const std::string &name) noexcept {
-    auto it = std::find(std::begin(level_string_views), std::end(level_string_views), name);
+    const auto *it = std::find(std::begin(level_string_views), std::end(level_string_views), name);
     if (it != std::end(level_string_views)) return static_cast<level>(std::distance(std::begin(level_string_views), it));
 
     // check also for "warn" and "err" before giving up
diff --git a/src/details/file_helper.cpp b/src/details/file_helper.cpp
index 96df3cbe..54aa2d2a 100644
--- a/src/details/file_helper.cpp
+++ b/src/details/file_helper.cpp
@@ -5,6 +5,7 @@
 
 #include <cerrno>
 #include <cstdio>
+#include <utility>
 
 #include "spdlog/common.h"
 #include "spdlog/details/os.h"
@@ -12,8 +13,8 @@
 namespace spdlog {
 namespace details {
 
-file_helper::file_helper(const file_event_handlers &event_handlers)
-    : event_handlers_(event_handlers) {}
+file_helper::file_helper(file_event_handlers event_handlers)
+    : event_handlers_(std::move(event_handlers)) {}
 
 file_helper::~file_helper() { close(); }
 
diff --git a/src/details/os_unix.cpp b/src/details/os_unix.cpp
index c1026b6d..f91fc69b 100644
--- a/src/details/os_unix.cpp
+++ b/src/details/os_unix.cpp
@@ -109,7 +109,7 @@ int rename(const filename_t &filename1, const filename_t &filename2) noexcept {
 
 // Return true if path exists (file or directory)
 bool path_exists(const filename_t &filename) noexcept {
-    struct stat buffer;
+    struct stat buffer{};
     return (::stat(filename.c_str(), &buffer) == 0);
 }
 
@@ -127,7 +127,7 @@ size_t filesize(FILE *f) {
 #endif
     // 64 bits(but not in osx, linux/musl or cygwin, where fstat64 is deprecated)
 #if ((defined(__linux__) && defined(__GLIBC__)) || defined(__sun) || defined(_AIX)) && (defined(__LP64__) || defined(_LP64))
-    struct stat64 st;
+    struct stat64 st{};
     if (::fstat64(fd, &st) == 0) {
         return static_cast<size_t>(st.st_size);
     }
@@ -275,7 +275,7 @@ bool is_color_terminal() noexcept {
 bool in_terminal(FILE *file) noexcept { return ::isatty(fileno(file)) != 0; }
 
 // return true on success
-static bool mkdir_(const filename_t &path) { return ::mkdir(path.c_str(), mode_t(0755)) == 0; }
+static bool mkdir_(const filename_t &path) { return ::mkdir(path.c_str(), static_cast<mode_t>(0755)) == 0; }
 
 // create the given directory - and all directories leading to it
 // return true on success or if the directory already exists
diff --git a/src/details/registry.cpp b/src/details/registry.cpp
index 1c53a16a..e60c7fd1 100644
--- a/src/details/registry.cpp
+++ b/src/details/registry.cpp
@@ -80,10 +80,9 @@ std::shared_ptr<logger> registry::get(const std::string &logger_name) {
             }
         }
         return nullptr;
-    } else {
-        auto found = loggers_.find(logger_name);
-        return found == loggers_.end() ? nullptr : found->second;
     }
+    auto found = loggers_.find(logger_name);
+    return found == loggers_.end() ? nullptr : found->second;
 }
 
 // if the map is small do a sequential search and avoid creating string for find(logger_name)
@@ -99,10 +98,8 @@ std::shared_ptr<logger> registry::get(std::string_view logger_name) {
         return nullptr;
     }
     // otherwise use the normal map lookup
-    else {
-        auto found = loggers_.find(std::string(logger_name));
-        return found == loggers_.end() ? nullptr : found->second;
-    }
+    const auto found = loggers_.find(std::string(logger_name));
+    return found == loggers_.end() ? nullptr : found->second;
 }
 
 std::shared_ptr<logger> registry::get(const char *logger_name) { return get(std::string_view(logger_name)); }
diff --git a/src/logger.cpp b/src/logger.cpp
index 4fc320e4..96dbcad6 100644
--- a/src/logger.cpp
+++ b/src/logger.cpp
@@ -40,9 +40,8 @@ void logger::set_formatter(std::unique_ptr<formatter> f) {
             // last element - we can move it.
             (*it)->set_formatter(std::move(f));
             break;  // to prevent clang-tidy warning
-        } else {
-            (*it)->set_formatter(f->clone());
         }
+        (*it)->set_formatter(f->clone());
     }
 }
 
diff --git a/src/pattern_formatter.cpp b/src/pattern_formatter.cpp
index 1dbbf318..a4c8620e 100644
--- a/src/pattern_formatter.cpp
+++ b/src/pattern_formatter.cpp
@@ -46,6 +46,9 @@ public:
         }
     }
 
+    scoped_padder(const scoped_padder &) = delete;
+    scoped_padder &operator=(const scoped_padder &) = delete;
+
     template <typename T>
     static unsigned int count_digits(T n) {
         return fmt_helper::count_digits(n);
@@ -127,7 +130,7 @@ static const char *ampm(const tm &t) { return t.tm_hour >= 12 ? "PM" : "AM"; }
 static int to12h(const tm &t) { return t.tm_hour > 12 ? t.tm_hour - 12 : t.tm_hour; }
 
 // Abbreviated weekday name
-static std::array<const char *, 7> days{{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}};
+static constexpr std::array<const char *, 7> days{{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}};
 
 template <typename ScopedPadder>
 class a_formatter final : public flag_formatter {
@@ -135,15 +138,15 @@ public:
     explicit a_formatter(padding_info padinfo)
         : flag_formatter(padinfo) {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
-        string_view_t field_value{days[static_cast<size_t>(tm_time.tm_wday)]};
+    void format(const log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
+        string_view_t field_value{days.at(static_cast<size_t>(tm_time.tm_wday))};
         ScopedPadder p(field_value.size(), padinfo_, dest);
         fmt_helper::append_string_view(field_value, dest);
     }
 };
 
 // Full weekday name
-static std::array<const char *, 7> full_days{{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}};
+static constexpr std::array<const char *, 7> full_days{{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}};
 
 template <typename ScopedPadder>
 class A_formatter final : public flag_formatter {
@@ -151,8 +154,8 @@ public:
     explicit A_formatter(padding_info padinfo)
         : flag_formatter(padinfo) {}
 
-    void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
-        string_view_t field_value{full_days[static_cast<size_t>(tm_time.tm_wday)]};
+    void format(const log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
+        string_view_t field_value{full_days.at(static_cast<size_t>(tm_time.tm_wday))};
         ScopedPadder p(field_value.size(), padinfo_, dest);
         fmt_helper::append_string_view(field_value, dest);
     }
@@ -169,7 +172,7 @@ public:
         : flag_formatter(padinfo) {}
 
     void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
-        string_view_t field_value{months[static_cast<size_t>(tm_time.tm_mon)]};
+        string_view_t field_value{months.at(static_cast<size_t>(tm_time.tm_mon))};
         ScopedPadder p(field_value.size(), padinfo_, dest);
         fmt_helper::append_string_view(field_value, dest);
     }
@@ -186,7 +189,7 @@ public:
         : flag_formatter(padinfo) {}
 
     void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
-        string_view_t field_value{full_months[static_cast<size_t>(tm_time.tm_mon)]};
+        string_view_t field_value{full_months.at(static_cast<size_t>(tm_time.tm_mon))};
         ScopedPadder p(field_value.size(), padinfo_, dest);
         fmt_helper::append_string_view(field_value, dest);
     }
@@ -203,9 +206,9 @@ public:
         const size_t field_size = 24;
         ScopedPadder p(field_size, padinfo_, dest);
 
-        fmt_helper::append_string_view(days[static_cast<size_t>(tm_time.tm_wday)], dest);
+        fmt_helper::append_string_view(days.at(static_cast<size_t>(tm_time.tm_wday)), dest);
         dest.push_back(' ');
-        fmt_helper::append_string_view(months[static_cast<size_t>(tm_time.tm_mon)], dest);
+        fmt_helper::append_string_view(months.at(static_cast<size_t>(tm_time.tm_mon)), dest);
         dest.push_back(' ');
         fmt_helper::append_int(tm_time.tm_mday, dest);
         dest.push_back(' ');
@@ -493,8 +496,11 @@ public:
         : flag_formatter(padinfo) {}
 
     z_formatter() = default;
+    ~z_formatter() override = default;
     z_formatter(const z_formatter &) = delete;
     z_formatter &operator=(const z_formatter &) = delete;
+    z_formatter(z_formatter &&) = delete;
+    z_formatter &operator=(z_formatter &&) = delete;
 
     void format(const details::log_msg &msg, const std::tm &tm_time, memory_buf_t &dest) override {
         const size_t field_size = 6;
@@ -626,12 +632,10 @@ public:
             return;
         }
 
-        size_t text_size;
+        size_t text_size = 0;
         if (padinfo_.enabled()) {
             // calc text size for padding based on "filename:line"
             text_size = std::char_traits<char>::length(msg.source.filename) + ScopedPadder::count_digits(msg.source.line) + 1;
-        } else {
-            text_size = 0;
         }
 
         ScopedPadder p(text_size, padinfo_, dest);
@@ -784,7 +788,7 @@ public:
         dest.push_back(' ');
 
         // append logger name if exists
-        if (msg.logger_name.size() > 0) {
+        if (!msg.logger_name.empty()) {
             dest.push_back('[');
             fmt_helper::append_string_view(msg.logger_name, dest);
             dest.push_back(']');
@@ -846,7 +850,7 @@ pattern_formatter::pattern_formatter(pattern_time_type time_type, std::string eo
 
 std::unique_ptr<formatter> pattern_formatter::clone() const {
     custom_flags cloned_custom_formatters;
-    for (auto &it : custom_handlers_) {
+    for (const auto &it : custom_handlers_) {
         cloned_custom_formatters[it.first] = it.second->clone();
     }
     auto cloned = std::make_unique<pattern_formatter>(pattern_, pattern_time_type_, eol_, std::move(cloned_custom_formatters));
@@ -1137,29 +1141,27 @@ details::padding_info pattern_formatter::handle_padspec_(std::string::const_iter
             ++it;
             break;
         default:
-            side = details::padding_info::pad_side::left;
+            side = padding_info::pad_side::left;
             break;
     }
 
-    if (it == end || !std::isdigit(static_cast<unsigned char>(*it))) {
+    if (it == end || (std::isdigit(static_cast<unsigned char>(*it)) == 0)) {
         return padding_info{};  // no padding if no digit found here
     }
 
     auto width = static_cast<size_t>(*it) - '0';
-    for (++it; it != end && std::isdigit(static_cast<unsigned char>(*it)); ++it) {
+    for (++it; it != end && (std::isdigit(static_cast<unsigned char>(*it)) != 0); ++it) {
         auto digit = static_cast<size_t>(*it) - '0';
         width = width * 10 + digit;
     }
 
     // search for the optional truncate marker '!'
-    bool truncate;
+    bool truncate = false;
     if (it != end && *it == '!') {
         truncate = true;
         ++it;
-    } else {
-        truncate = false;
     }
-    return details::padding_info{std::min<size_t>(width, max_width), side, truncate};
+    return padding_info{std::min<size_t>(width, max_width), side, truncate};
 }
 
 void pattern_formatter::compile_pattern_(const std::string &pattern) {
diff --git a/src/sinks/rotating_file_sink.cpp b/src/sinks/rotating_file_sink.cpp
index b6a46ff5..5b2fad84 100644
--- a/src/sinks/rotating_file_sink.cpp
+++ b/src/sinks/rotating_file_sink.cpp
@@ -45,11 +45,12 @@ rotating_file_sink<Mutex>::rotating_file_sink(filename_t base_filename,
 // e.g. calc_filename("logs/mylog.txt, 3) => "logs/mylog.3.txt".
 template <typename Mutex>
 filename_t rotating_file_sink<Mutex>::calc_filename(const filename_t &filename, std::size_t index) {
-    if (index == 0u) {
+    if (index == 0U) {
         return filename;
     }
 
-    filename_t basename, ext;
+    filename_t basename;
+    filename_t ext;
     std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
     return fmt_lib::format(SPDLOG_FMT_STRING(SPDLOG_FILENAME_T("{}.{}{}")), basename, index, ext);
 }