diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 594f5cc..c569600 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_executable(tmx2gba
+	strtools.hpp strtools.cpp
 	argparse.hpp argparse.cpp
 	$<$<NOT:$<TARGET_EXISTS:ZLIB::ZLIB>>:gzip.hpp gzip.cpp>
 	tmxlayer.hpp
diff --git a/src/strtools.cpp b/src/strtools.cpp
new file mode 100644
index 0000000..3ad5c6f
--- /dev/null
+++ b/src/strtools.cpp
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: Zlib
+// SPDX-FileCopyrightText: (c) 2015-2024 a dinosaur
+
+#include "strtools.hpp"
+#include <cctype>
+#include <algorithm>
+
+
+const std::string_view TrimWhitespace(const std::string_view str)
+{
+	auto beg = std::find_if_not(str.begin(), str.end(), ::isspace);
+	if (beg == std::end(str))
+	{
+		return {};
+	}
+	auto end = std::find_if_not(str.rbegin(), str.rend(), ::isspace);
+	auto begOff = std::distance(str.begin(), beg);
+	auto endOff = std::distance(end, str.rend()) - begOff;
+	using size_type = std::string::size_type;
+	return str.substr(static_cast<size_type>(begOff), static_cast<size_type>(endOff));
+}
+
+std::string SanitiseLabel(const std::string_view ident)
+{
+	std::string out;
+	out.reserve(ident.length());
+
+	int last = '_';
+	for (int i : ident)
+	{
+		if (out.empty() && std::isdigit(i)) { continue; }
+		if (!std::isalnum(i))               { i = '_'; }
+		if (i != '_' || last != '_')        { out.push_back(i); }
+		last = i;
+	}
+	return out;
+}
diff --git a/src/strtools.hpp b/src/strtools.hpp
new file mode 100644
index 0000000..ad0d0d7
--- /dev/null
+++ b/src/strtools.hpp
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: Zlib
+// SPDX-FileCopyrightText: (c) 2024 a dinosaur
+
+#ifndef STRTOOLS_HPP
+#define STRTOOLS_HPP
+
+#include <string>
+#include <string_view>
+
+// Cut leading & trailing whitespace (including newlines)
+[[nodiscard]] const std::string_view TrimWhitespace(const std::string_view str);
+
+// Convert string to valid C identifier
+[[nodiscard]] std::string SanitiseLabel(const std::string_view ident);
+
+
+#include <ostream>
+
+// Template functions for converting unsigned ints to C/GNU style hex
+
+static inline constexpr char CHexU(uint8_t h) { return "0123456789ABCDEF"[h >> 4]; }
+static inline constexpr char CHexL(uint8_t l) { return "0123456789ABCDEF"[l & 15]; }
+
+template <typename T> static void CHex(std::ostream& s, T x);
+template <> void CHex(std::ostream& s, uint8_t x)
+{
+	if (x >  9) s << "0x";
+	if (x > 15) s << CHexU(x);
+	s << CHexL(x);
+}
+template <> void CHex(std::ostream& s, uint16_t x)
+{
+	if (x >    9) s << "0x";
+	if (x > 4095) s << CHexU(static_cast<uint8_t>(x >> 8));
+	if (x >  255) s << CHexL(static_cast<uint8_t>(x >> 8));
+	if (x >   15) s << CHexU(static_cast<uint8_t>(x));
+	s << CHexL(static_cast<uint8_t>(x));
+}
+template <> void CHex(std::ostream& s, uint32_t x)
+{
+	if (x >         9) s << "0x";
+	if (x > 0xFFFFFFF) s << CHexU(static_cast<uint8_t>(x >> 24));
+	if (x >  0xFFFFFF) s << CHexL(static_cast<uint8_t>(x >> 24));
+	if (x >   0xFFFFF) s << CHexU(static_cast<uint8_t>(x >> 16));
+	if (x >     65535) s << CHexL(static_cast<uint8_t>(x >> 16));
+	if (x >      4095) s << CHexU(static_cast<uint8_t>(x >>  8));
+	if (x >       255) s << CHexL(static_cast<uint8_t>(x >>  8));
+	if (x >        15) s << CHexU(static_cast<uint8_t>(x));
+	s << CHexL(static_cast<uint8_t>(x));
+}
+
+
+#include <limits>
+#include <cstdlib>
+#include <optional>
+
+// Templated string to int/float w/ exception-less error handling
+
+template <typename T>
+[[nodiscard]] static std::optional<T> IntFromStr(const char* str, int base = 0) noexcept
+{
+	using std::numeric_limits;
+
+	errno = 0;
+	char* end = nullptr;
+	long res = std::strtol(str, &end, base);
+	if (errno == ERANGE) { return std::nullopt; }
+	if (str == end) { return std::nullopt; }
+	if constexpr (sizeof(long) > sizeof(T))
+	{
+		if (res > numeric_limits<T>::max() || res < numeric_limits<T>::min())
+			return std::nullopt;
+	}
+
+	return static_cast<T>(res);
+}
+
+template <typename T>
+[[nodiscard]] static std::optional<T> UintFromStr(const char* str, int base = 0) noexcept
+{
+	using std::numeric_limits;
+
+	char* end = nullptr;
+	errno = 0;
+	unsigned long res = std::strtoul(str, &end, base);
+	if (errno == ERANGE) { return std::nullopt; }
+	if (str == end) { return std::nullopt; }
+	if constexpr (numeric_limits<unsigned long>::max() > numeric_limits<T>::max())
+	{
+		if (res > numeric_limits<T>::max()) { return std::nullopt; }
+	}
+
+	return static_cast<T>(res);
+}
+
+template <typename T>
+[[nodiscard]] static std::optional<T> FloatFromStr(const char* str) noexcept
+{
+	char* end = nullptr;
+	T res;
+	errno = 0;
+	if constexpr (std::is_same_v<T, float>)
+		res = std::strtof(str, &end);
+	else
+		res = static_cast<T>(std::strtod(str, &end));
+	if (errno == ERANGE) { return std::nullopt; }
+	if (str == end) { return std::nullopt; }
+
+	return res;
+}
+
+#endif//STRTOOLS_HPP
diff --git a/src/swriter.cpp b/src/swriter.cpp
index ebe6595..b703b10 100644
--- a/src/swriter.cpp
+++ b/src/swriter.cpp
@@ -2,43 +2,11 @@
 // SPDX-FileCopyrightText: (c) 2024 a dinosaur
 
 #include "swriter.hpp"
+#include "strtools.hpp"
 #include <type_traits>
-#include <limits>
 #include <assert.h>
 
 
-static inline constexpr char HexU(uint8_t h) { return "0123456789ABCDEF"[h >> 4]; }
-static inline constexpr char HexL(uint8_t l) { return "0123456789ABCDEF"[l & 15]; }
-
-template <typename T> static void CHex(std::ostream& s, T x);
-template <> void CHex(std::ostream& s, uint8_t x)
-{
-	if (x >  9) s << "0x";
-	if (x > 15) s << HexU(x);
-	s << HexL(x);
-}
-template <> void CHex(std::ostream& s, uint16_t x)
-{
-	if (x >    9) s << "0x";
-	if (x > 4095) s << HexU(static_cast<uint8_t>(x >> 8));
-	if (x >  255) s << HexL(static_cast<uint8_t>(x >> 8));
-	if (x >   15) s << HexU(static_cast<uint8_t>(x));
-	s << HexL(static_cast<uint8_t>(x));
-}
-template <> void CHex(std::ostream& s, uint32_t x)
-{
-	if (x >         9) s << "0x";
-	if (x > 0xFFFFFFF) s << HexU(static_cast<uint8_t>(x >> 24));
-	if (x >  0xFFFFFF) s << HexL(static_cast<uint8_t>(x >> 24));
-	if (x >   0xFFFFF) s << HexU(static_cast<uint8_t>(x >> 16));
-	if (x >     65535) s << HexL(static_cast<uint8_t>(x >> 16));
-	if (x >      4095) s << HexU(static_cast<uint8_t>(x >>  8));
-	if (x >       255) s << HexL(static_cast<uint8_t>(x >>  8));
-	if (x >        15) s << HexU(static_cast<uint8_t>(x));
-	s << HexL(static_cast<uint8_t>(x));
-}
-
-
 template <typename T> static constexpr const std::string_view DataType();
 template <> constexpr const std::string_view DataType<uint8_t>()  { return ".byte"; }
 template <> constexpr const std::string_view DataType<uint16_t>() { return ".hword"; }
diff --git a/src/tmx2gba.cpp b/src/tmx2gba.cpp
index 7fa9d4c..e5c74f7 100644
--- a/src/tmx2gba.cpp
+++ b/src/tmx2gba.cpp
@@ -10,6 +10,7 @@ constexpr std::string_view copyrightStr("(c) 2015-2024 a dinosaur");
 #include "convert.hpp"
 #include "headerwriter.hpp"
 #include "swriter.hpp"
+#include "strtools.hpp"
 #include "config.h"
 #include <iostream>
 #include <map>
@@ -115,26 +116,6 @@ static bool ParseArgs(int argc, char** argv, Arguments& params)
 	return true;
 }
 
-
-static std::string SanitiseLabel(const std::string_view ident)
-{
-	std::string out;
-	out.reserve(ident.length());
-
-	int last = '_';
-	for (int i : ident)
-	{
-		if (out.empty() && std::isdigit(i))
-			continue;
-		if (!std::isalnum(i))
-			i = '_';
-		if (i != '_' || last != '_')
-			out.push_back(i);
-		last = i;
-	}
-	return out;
-}
-
 int main(int argc, char** argv)
 {
 	Arguments p;
diff --git a/src/tmxmap.cpp b/src/tmxmap.cpp
index 4dbba55..3d91b0e 100644
--- a/src/tmxmap.cpp
+++ b/src/tmxmap.cpp
@@ -2,6 +2,7 @@
 // SPDX-FileCopyrightText: (c) 2015-2024 a dinosaur
 
 #include "tmxmap.hpp"
+#include "strtools.hpp"
 #include "config.h"
 #include <pugixml.hpp>
 #include <base64.h>
@@ -11,80 +12,10 @@
 # include "gzip.hpp"
 #endif
 #include <zstd.h>
-#include <limits>
 #include <cerrno>
-#include <optional>
 #include <algorithm>
 
 
-template <typename T>
-[[nodiscard]] static std::optional<T> IntFromStr(const char* str, int base = 0) noexcept
-{
-	using std::numeric_limits;
-
-	errno = 0;
-	char* end = nullptr;
-	long res = std::strtol(str, &end, base);
-	if (errno == ERANGE) { return std::nullopt; }
-	if (str == end) { return std::nullopt; }
-	if constexpr (sizeof(long) > sizeof(T))
-	{
-		if (res > numeric_limits<T>::max() || res < numeric_limits<T>::min())
-			return std::nullopt;
-	}
-
-	return static_cast<T>(res);
-}
-
-template <typename T>
-[[nodiscard]] static std::optional<T> UintFromStr(const char* str, int base = 0) noexcept
-{
-	using std::numeric_limits;
-
-	char* end = nullptr;
-	errno = 0;
-	unsigned long res = std::strtoul(str, &end, base);
-	if (errno == ERANGE) { return std::nullopt; }
-	if (str == end) { return std::nullopt; }
-	if constexpr (numeric_limits<unsigned long>::max() > numeric_limits<T>::max())
-	{
-		if (res > numeric_limits<T>::max()) { return std::nullopt; }
-	}
-
-	return static_cast<T>(res);
-}
-
-template <typename T>
-[[nodiscard]] static std::optional<T> FloatFromStr(const char* str) noexcept
-{
-	char* end = nullptr;
-	T res;
-	errno = 0;
-	if constexpr (std::is_same_v<T, float>)
-		res = std::strtof(str, &end);
-	else
-		res = static_cast<T>(std::strtod(str, &end));
-	if (errno == ERANGE) { return std::nullopt; }
-	if (str == end) { return std::nullopt; }
-
-	return res;
-}
-
-[[nodiscard]] static std::optional<std::string> UnBase64(const std::string_view base64)
-{
-	// Cut leading & trailing whitespace (including newlines)
-	auto beg = std::find_if_not(base64.begin(), base64.end(), ::isspace);
-	if (beg == std::end(base64)) { return std::nullopt; }
-	auto end = std::find_if_not(base64.rbegin(), base64.rend(), ::isspace);
-	auto begOff = std::distance(base64.begin(), beg);
-	auto endOff = std::distance(end, base64.rend()) - begOff;
-	using size_type = std::string::size_type;
-	const auto trimmed = base64.substr(static_cast<size_type>(begOff), static_cast<size_type>(endOff));
-
-	// Decode base64 string
-	return base64_decode(trimmed);
-}
-
 enum class Encoding { XML, BASE64, CSV, INVALID };
 enum class Compression { NONE, GZIP, ZLIB, ZSTD, INVALID };
 
@@ -105,6 +36,7 @@ enum class Compression { NONE, GZIP, ZLIB, ZSTD, INVALID };
 	return Compression::INVALID;
 }
 
+
 [[nodiscard]] static bool Decompress(Compression compression, std::span<uint32_t> out, const std::string_view decoded)
 {
 	//FIXME: lmao what is big endian
@@ -192,22 +124,22 @@ void TmxMap::ReadLayer(const pugi::xml_node& xNode)
 	if (encoding == Encoding::BASE64)
 	{
 		// Decode base64 string
-		auto decoded = UnBase64(xData.child_value());
-		if (!decoded.has_value())
+		auto decoded = base64_decode(TrimWhitespace(xData.child_value()));
+		if (decoded.empty())
 			return;
 
 		auto compression = CompressionFromStr(xData.attribute("compression").value());
 		if (compression == Compression::GZIP || compression == Compression::ZLIB || compression == Compression::ZSTD)
 		{
 			tileDat.resize(numTiles);
-			if (!Decompress(compression, tileDat, decoded.value()))
+			if (!Decompress(compression, tileDat, decoded))
 				return;
 		}
 		else if (compression == Compression::NONE)
 		{
 			tileDat.reserve(numTiles);
-			const auto end = decoded.value().end();
-			for (auto it = decoded.value().begin(); it < end - 3;)
+			const auto end = decoded.end();
+			for (auto it = decoded.begin(); it < end - 3;)
 			{
 				uint32_t tile = static_cast<uint32_t>(static_cast<uint8_t>(*it++));
 				tile |= static_cast<uint32_t>(static_cast<uint8_t>(*it++)) << 8u;