diff --git a/test/tools/yulInterpreter/CMakeLists.txt b/test/tools/yulInterpreter/CMakeLists.txt
index d3ddac13d..cc1b40f07 100644
--- a/test/tools/yulInterpreter/CMakeLists.txt
+++ b/test/tools/yulInterpreter/CMakeLists.txt
@@ -5,6 +5,8 @@ set(sources
 	EwasmBuiltinInterpreter.cpp
 	Interpreter.h
 	Interpreter.cpp
+	Inspector.h
+	Inspector.cpp
 )
 
 add_library(yulInterpreter ${sources})
diff --git a/test/tools/yulInterpreter/Inspector.cpp b/test/tools/yulInterpreter/Inspector.cpp
new file mode 100644
index 000000000..3ded7367f
--- /dev/null
+++ b/test/tools/yulInterpreter/Inspector.cpp
@@ -0,0 +1,156 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// SPDX-License-Identifier: GPL-3.0
+/**
+ * Yul interpreter.
+ */
+
+#include <test/tools/yulInterpreter/Inspector.h>
+
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/algorithm/string.hpp>
+
+using namespace solidity;
+using namespace solidity::yul;
+using namespace solidity::yul::test;
+
+using namespace std;
+
+namespace
+{
+
+void printVariable(YulString const& _name, u256 const& _value)
+{
+	cout << "\t" << _name.str() << " = " << _value.str();
+
+	if (_value != 0)
+		cout << " (" << toCompactHexWithPrefix(_value) << ")";
+
+	cout << endl;
+}
+
+}
+
+void InspectedInterpreter::run(
+	std::shared_ptr<Inspector> _inspector,
+	InterpreterState& _state,
+	Dialect const& _dialect,
+	Block const& _ast,
+	bool _disableExternalCalls,
+	bool _disableMemoryTrace
+)
+{
+	Scope scope;
+	InspectedInterpreter{_inspector, _state, _dialect, scope, _disableExternalCalls, _disableMemoryTrace}(_ast);
+}
+
+Inspector::NodeAction Inspector::queryUser(DebugData const& _data, map<YulString, u256> const& _variables)
+{
+	if (m_stepMode == NodeAction::RunNode)
+	{
+		// Output instructions that are being skipped/run
+		cout << "Running " << currentSource(_data) << endl;
+
+		return NodeAction::StepThroughNode;
+	}
+
+	string input;
+
+	while (true)
+	{
+		// Output sourcecode about to run.
+		cout << "> " << currentSource(_data) << endl;
+
+		// Ask user for action
+		cout << endl
+			<< "(s)tep/(n)ext/(i)nspect/(p)rint/all (v)ariables?"
+			<< endl
+			<< "# ";
+
+		cout.flush();
+
+		getline(cin, input);
+		boost::algorithm::trim(input);
+
+		// Imitate GDB and repeat last cmd for empty string input.
+		if (input == "")
+			input = m_lastInput;
+		else
+			m_lastInput = input;
+
+		if (input == "next" || input == "n")
+			return NodeAction::RunNode;
+		else if (input == "step" || input == "s")
+			return NodeAction::StepThroughNode;
+		else if (input == "inspect" || input == "i")
+			m_state.dumpTraceAndState(cout, false);
+		else if (input == "variables" || input == "v")
+		{
+			for (auto &&[yulStr, val]: _variables)
+				printVariable(yulStr, val);
+			cout << endl;
+		}
+		else if (
+			boost::starts_with(input, "print") ||
+			boost::starts_with(input, "p")
+		)
+		{
+			size_t whitespacePos = input.find(' ');
+
+			if (whitespacePos == string::npos)
+				cout << "Error parsing command! Expected variable name." << endl;
+
+			string const varname = input.substr(whitespacePos + 1);
+
+			vector<string> candidates;
+
+			bool found = false;
+			for (auto &&[yulStr, val]: _variables)
+				if (yulStr.str() == varname)
+				{
+					printVariable(yulStr, val);
+					found = true;
+					break;
+				}
+
+			if (!found)
+				cout << varname << " not found." << endl;
+		}
+	}
+}
+
+std::string Inspector::currentSource(DebugData const& _data) const
+{
+	return m_source.substr(
+		static_cast<size_t>(_data.nativeLocation.start),
+		static_cast<size_t>(_data.nativeLocation.end - _data.nativeLocation.start)
+	);
+}
+
+u256 InspectedInterpreter::evaluate(Expression const& _expression)
+{
+	InspectedExpressionEvaluator ev(m_inspector, m_state, m_dialect, *m_scope, m_variables, m_disableExternalCalls, m_disableMemoryTrace);
+	ev.visit(_expression);
+	return ev.value();
+}
+
+std::vector<u256> InspectedInterpreter::evaluateMulti(Expression const& _expression)
+{
+	InspectedExpressionEvaluator ev(m_inspector, m_state, m_dialect, *m_scope, m_variables, m_disableExternalCalls, m_disableMemoryTrace);
+	ev.visit(_expression);
+	return ev.values();
+}
diff --git a/test/tools/yulInterpreter/Inspector.h b/test/tools/yulInterpreter/Inspector.h
new file mode 100644
index 000000000..611279c6f
--- /dev/null
+++ b/test/tools/yulInterpreter/Inspector.h
@@ -0,0 +1,213 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// SPDX-License-Identifier: GPL-3.0
+/**
+ * Yul inspector.
+ */
+
+#include <test/tools/yulInterpreter/Interpreter.h>
+
+#include <libyul/AST.h>
+
+#include <string>
+
+#pragma once
+
+namespace solidity::yul::test
+{
+
+/**
+ * Inspector class to respond to queries by the user for:
+ *
+ * * Stepping through and over instructions.
+ * * Printing a specific or all variables.
+ * * Inspecting memory, storage and calldata memory.
+ */
+class Inspector
+{
+public:
+	enum class NodeAction
+	{
+		RunNode,
+		StepThroughNode,
+	};
+
+	Inspector(std::string const& _source, InterpreterState const& _state)
+		:m_source(_source), m_state(_state) {}
+
+	/* Asks the user what action to take.
+	 * @returns NodeAction::RunNode if the current AST node (and all children nodes!) should be
+	 *          processed without stopping, else NodeAction::StepThroughNode.
+	 */
+	NodeAction queryUser(DebugData const& _data, std::map<YulString, u256> const& _variables);
+
+	void stepMode(NodeAction _action) { m_stepMode = _action; }
+
+	std::string const& source() const { return m_source; }
+
+	void interactiveVisit(DebugData const& _debugData, std::map<YulString, u256> const& _variables, std::function<void()> _visitNode)
+	{
+		Inspector::NodeAction action = queryUser(_debugData, _variables);
+
+		if (action == NodeAction::RunNode)
+		{
+			// user requested to run the whole node without stopping
+			stepMode(Inspector::NodeAction::RunNode);
+
+			_visitNode();
+
+			// Reset step mode back
+			stepMode(Inspector::NodeAction::StepThroughNode);
+		}
+		else
+			_visitNode();
+	}
+
+private:
+	std::string currentSource(DebugData const& _data) const;
+
+	/// Source of the file
+	std::string const& m_source;
+
+	/// State of the interpreter
+	InterpreterState const& m_state;
+
+	/// Last user query command
+	std::string m_lastInput;
+
+	/// Used to run AST nodes without user interaction
+	NodeAction m_stepMode = NodeAction::StepThroughNode;
+};
+
+/**
+ * Yul Interpreter with inspection. Allows the user to go through the code step
+ * by step and inspect the state using the `Inspector` class
+ */
+class InspectedInterpreter: public Interpreter
+{
+public:
+	static void run(
+		std::shared_ptr<Inspector> _inspector,
+		InterpreterState& _state,
+		Dialect const& _dialect,
+		Block const& _ast,
+		bool _disableExternalCalls,
+		bool _disableMemoryTracing
+	);
+
+	InspectedInterpreter(
+		std::shared_ptr<Inspector> _inspector,
+		InterpreterState& _state,
+		Dialect const& _dialect,
+		Scope& _scope,
+		bool _disableExternalCalls,
+		bool _disableMemoryTracing,
+		std::map<YulString, u256> _variables = {}
+	):
+		Interpreter(_state, _dialect, _scope, _disableExternalCalls, _disableMemoryTracing, _variables),
+		m_inspector(_inspector)
+	{
+	}
+
+	void operator()(ExpressionStatement const& _node) override { helper(_node); }
+	void operator()(Assignment const& _node) override { helper(_node); }
+	void operator()(VariableDeclaration const& _node) override { helper(_node); }
+	void operator()(If const& _node) override { helper(_node); }
+	void operator()(Switch const& _node) override { helper(_node); }
+	void operator()(ForLoop const& _node) override { helper(_node); }
+	void operator()(Break const& _node) override { helper(_node); }
+	void operator()(Continue const& _node) override { helper(_node); }
+	void operator()(Leave const& _node) override { helper(_node); }
+	void operator()(Block const& _node) override { helper(_node); }
+protected:
+	/// Asserts that the expression evaluates to exactly one value and returns it.
+	u256 evaluate(Expression const& _expression) override;
+	/// Evaluates the expression and returns its value.
+	std::vector<u256> evaluateMulti(Expression const& _expression) override;
+private:
+	std::shared_ptr<Inspector> m_inspector;
+
+	template <typename ConcreteNode>
+	void helper(ConcreteNode const& _node)
+	{
+		m_inspector->interactiveVisit(*_node.debugData, m_variables, [&]() {
+			Interpreter::operator()(_node);
+		});
+	}
+
+};
+
+
+class InspectedExpressionEvaluator: public ExpressionEvaluator
+{
+public:
+	InspectedExpressionEvaluator(
+		std::shared_ptr<Inspector> _inspector,
+		InterpreterState& _state,
+		Dialect const& _dialect,
+		Scope& _scope,
+		std::map<YulString, u256> const& _variables,
+		bool _disableExternalCalls,
+		bool _disableMemoryTrace
+	):
+		ExpressionEvaluator(_state, _dialect, _scope, _variables, _disableExternalCalls, _disableMemoryTrace),
+		m_inspector(_inspector)
+	{}
+
+	template <typename ConcreteNode>
+	void helper(ConcreteNode const& _node)
+	{
+		m_inspector->interactiveVisit(*_node.debugData, m_variables, [&]() {
+			ExpressionEvaluator::operator()(_node);
+		});
+	}
+
+	void operator()(Literal const& _node) override { helper(_node); }
+	void operator()(Identifier const& _node) override { helper(_node); }
+	void operator()(FunctionCall const& _node) override { helper(_node); }
+protected:
+	std::unique_ptr<Interpreter> makeInterpreterCopy(std::map<YulString, u256> _variables = {}) const override
+	{
+		return std::make_unique<InspectedInterpreter>(
+			m_inspector,
+			m_state,
+			m_dialect,
+			m_scope,
+			m_disableExternalCalls,
+			m_disableMemoryTrace,
+			std::move(_variables)
+		);
+	}
+	std::unique_ptr<Interpreter> makeInterpreterNew(InterpreterState& _state, Scope& _scope) const override
+	{
+		return std::make_unique<InspectedInterpreter>(
+			std::make_unique<Inspector>(
+				m_inspector->source(),
+				_state
+			),
+			_state,
+			m_dialect,
+			_scope,
+			m_disableExternalCalls,
+			m_disableMemoryTrace
+		);
+	}
+private:
+	std::shared_ptr<Inspector> m_inspector;
+};
+
+}
diff --git a/test/tools/yulInterpreter/Interpreter.cpp b/test/tools/yulInterpreter/Interpreter.cpp
index f24f8b7f1..9add48509 100644
--- a/test/tools/yulInterpreter/Interpreter.cpp
+++ b/test/tools/yulInterpreter/Interpreter.cpp
@@ -72,6 +72,34 @@ void InterpreterState::dumpTraceAndState(ostream& _out, bool _disableMemoryTrace
 	}
 	_out << "Storage dump:" << endl;
 	dumpStorage(_out);
+
+	if (!calldata.empty())
+	{
+		_out << "Calldata dump:";
+
+		for (size_t offset = 0; offset < calldata.size(); ++offset)
+			if (calldata[offset] != 0)
+			{
+				if (offset % 32 == 0)
+					_out <<
+						std::endl <<
+						"  " <<
+						std::uppercase <<
+						std::hex <<
+						std::setfill(' ') <<
+						std::setw(4) <<
+						offset <<
+						": ";
+
+				_out <<
+					std::hex <<
+					std::setw(2) <<
+					std::setfill('0') <<
+					static_cast<int>(calldata[offset]);
+			}
+
+		_out << endl;
+	}
 }
 
 void Interpreter::run(
diff --git a/test/tools/yulInterpreter/Interpreter.h b/test/tools/yulInterpreter/Interpreter.h
index 3eee09caa..5dcb328d9 100644
--- a/test/tools/yulInterpreter/Interpreter.h
+++ b/test/tools/yulInterpreter/Interpreter.h
@@ -188,11 +188,11 @@ public:
 
 	u256 valueOfVariable(YulString _name) const { return m_variables.at(_name); }
 
-private:
+protected:
 	/// Asserts that the expression evaluates to exactly one value and returns it.
-	u256 evaluate(Expression const& _expression);
+	virtual u256 evaluate(Expression const& _expression);
 	/// Evaluates the expression and returns its value.
-	std::vector<u256> evaluateMulti(Expression const& _expression);
+	virtual std::vector<u256> evaluateMulti(Expression const& _expression);
 
 	void enterScope(Block const& _block);
 	void leaveScope();
@@ -206,6 +206,8 @@ private:
 	/// Values of variables.
 	std::map<YulString, u256> m_variables;
 	Scope* m_scope;
+	/// If not set, external calls (e.g. using `call()`) to the same contract
+	/// are evaluated in a new parser instance.
 	bool m_disableExternalCalls;
 	bool m_disableMemoryTrace;
 };
@@ -241,7 +243,7 @@ public:
 	/// Returns the list of values of the expression.
 	std::vector<u256> values() const { return m_values; }
 
-private:
+protected:
 	void runExternalCall(evmasm::Instruction _instruction);
 	virtual std::unique_ptr<Interpreter> makeInterpreterCopy(std::map<YulString, u256> _variables = {}) const
 	{
diff --git a/test/tools/yulrun.cpp b/test/tools/yulrun.cpp
index 4a273d371..eee342470 100644
--- a/test/tools/yulrun.cpp
+++ b/test/tools/yulrun.cpp
@@ -20,6 +20,7 @@
  */
 
 #include <test/tools/yulInterpreter/Interpreter.h>
+#include <test/tools/yulInterpreter/Inspector.h>
 
 #include <libyul/AsmAnalysisInfo.h>
 #include <libyul/AsmAnalysis.h>
@@ -74,7 +75,7 @@ pair<shared_ptr<Block>, shared_ptr<AsmAnalysisInfo>> parse(string const& _source
 	}
 }
 
-void interpret(string const& _source, bool _disableExternalCalls)
+void interpret(string const& _source, bool _inspect, bool _disableExternalCalls)
 {
 	shared_ptr<Block> ast;
 	shared_ptr<AsmAnalysisInfo> analysisInfo;
@@ -87,7 +88,12 @@ void interpret(string const& _source, bool _disableExternalCalls)
 	try
 	{
 		Dialect const& dialect(EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion{}));
-		Interpreter::run(state, dialect, *ast, _disableExternalCalls, /*disableMemoryTracing=*/false);
+
+		if (_inspect)
+			InspectedInterpreter::run(std::make_shared<Inspector>(_source, state), state, dialect, *ast, _disableExternalCalls, /*disableMemoryTracing=*/false);
+
+		else
+			Interpreter::run(state, dialect, *ast, _disableExternalCalls, /*disableMemoryTracing=*/false);
 	}
 	catch (InterpreterTerminatedGeneric const&)
 	{
@@ -111,6 +117,7 @@ Allowed options)",
 	options.add_options()
 		("help", "Show this help screen.")
 		("enable-external-calls", "Enable external calls")
+		("interactive", "Run interactive")
 		("input-file", po::value<vector<string>>(), "input file");
 	po::positional_options_description filesPositions;
 	filesPositions.add("input-file", -1);
@@ -154,7 +161,7 @@ Allowed options)",
 		else
 			input = readUntilEnd(cin);
 
-		interpret(input, !arguments.count("enable-external-calls"));
+		interpret(input, arguments.count("interactive"), !arguments.count("enable-external-calls"));
 	}
 
 	return 0;