diff --git a/source/MRMesh/MRMesh.vcxproj b/source/MRMesh/MRMesh.vcxproj
index 8e948f8493a3..ccc6bd59c3cd 100644
--- a/source/MRMesh/MRMesh.vcxproj
+++ b/source/MRMesh/MRMesh.vcxproj
@@ -257,6 +257,8 @@
     <ClInclude Include="MRVoxelsVolume.h" />
     <ClInclude Include="MRWriter.h" />
     <ClInclude Include="MRXfBasedCache.h" />
+    <ClInclude Include="MRPolylineRelax.h" />
+    <ClInclude Include="MRRelaxParams.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="MR2DContoursTriangulation.cpp" />
@@ -459,6 +461,7 @@
     <ClCompile Include="MRVDBConversions.cpp" />
     <ClCompile Include="MRObjectDistanceMap.cpp" />
     <ClCompile Include="MRVoxelsVolume.cpp" />
+    <ClCompile Include="MRPolylineRelax.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\MRPch\MRPch.vcxproj">
diff --git a/source/MRMesh/MRMesh.vcxproj.filters b/source/MRMesh/MRMesh.vcxproj.filters
index 143b3846d8cd..886fc545462d 100644
--- a/source/MRMesh/MRMesh.vcxproj.filters
+++ b/source/MRMesh/MRMesh.vcxproj.filters
@@ -604,7 +604,7 @@
       <Filter>Source Files\AABBTree</Filter>
     </ClInclude>
     <ClInclude Include="MRPointCloudRelax.h">
-      <Filter>Source Files\PointCloud</Filter>
+      <Filter>Source Files\Relax</Filter>
     </ClInclude>
     <ClInclude Include="MRBestFitQuadric.h">
       <Filter>Source Files\Math</Filter>
@@ -733,7 +733,7 @@
       <Filter>Source Files\Mesh</Filter>
     </ClInclude>
     <ClInclude Include="MRMeshRelax.h">
-      <Filter>Source Files\MeshAlgorithm</Filter>
+      <Filter>Source Files\Relax</Filter>
     </ClInclude>
     <ClInclude Include="MRMeshToPointCloud.h">
       <Filter>Source Files\MeshAlgorithm</Filter>
@@ -843,6 +843,12 @@
     <ClInclude Include="MRChangePolylineAction.h">
       <Filter>Source Files\History</Filter>
     </ClInclude>
+    <ClInclude Include="MRPolylineRelax.h">
+      <Filter>Source Files\Relax</Filter>
+    </ClInclude>
+    <ClInclude Include="MRRelaxParams.h">
+      <Filter>Source Files\Relax</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="MRId.cpp">
@@ -1427,6 +1433,9 @@
     <ClCompile Include="MRPolylineSubdivide.cpp">
       <Filter>Source Files\Polyline</Filter>
     </ClCompile>
+    <ClCompile Include="MRPolylineRelax.cpp">
+      <Filter>Source Files\Polyline</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\.editorconfig" />
diff --git a/source/MRMesh/MRMeshRelax.h b/source/MRMesh/MRMeshRelax.h
index f9b52723128a..6f89d55d9145 100644
--- a/source/MRMesh/MRMeshRelax.h
+++ b/source/MRMesh/MRMeshRelax.h
@@ -1,6 +1,7 @@
 #pragma once
 #include "MRMeshFwd.h"
 #include "MRProgressCallback.h"
+#include "MRRelaxParams.h"
 
 namespace MR
 {
@@ -9,16 +10,6 @@ namespace MR
 /// \ingroup MeshAlgorithmGroup
 /// \{
 
-struct RelaxParams
-{
-    /// number of iterations
-    int iterations{ 1 };
-    /// region to relax
-    const VertBitSet* region{ nullptr };
-    /// speed of relaxing, typical values (0.0, 0.5]
-    float force{ 0.5f };
-};
-
 struct MeshRelaxParams : RelaxParams
 {
     /// smooth tetrahedron verts (with complete three edges ring) to base triangle (based on its edges destinations)
@@ -34,12 +25,6 @@ MRMESH_API bool relax( Mesh& mesh, const MeshRelaxParams& params = {}, ProgressC
 /// \return true if was finished successfully, false if was interrupted by progress callback
 MRMESH_API bool relaxKeepVolume( Mesh& mesh, const MeshRelaxParams& params = {}, ProgressCallback cb = {} );
 
-enum class RelaxApproxType 
-{
-    Planar,
-    Quadric
-};
-
 struct MeshApproxRelaxParams : MeshRelaxParams
 {
     /// radius to find neighbors by surface
diff --git a/source/MRMesh/MRPointCloudRelax.h b/source/MRMesh/MRPointCloudRelax.h
index 89ea45e4404e..21488a75ac5b 100644
--- a/source/MRMesh/MRPointCloudRelax.h
+++ b/source/MRMesh/MRPointCloudRelax.h
@@ -1,6 +1,7 @@
 #pragma once
 #include "MRMeshFwd.h"
-#include "MRMeshRelax.h"
+#include "MRProgressCallback.h"
+#include "MRRelaxParams.h"
 
 namespace MR
 {
diff --git a/source/MRMesh/MRPolylineRelax.cpp b/source/MRMesh/MRPolylineRelax.cpp
new file mode 100644
index 000000000000..783e84c1da49
--- /dev/null
+++ b/source/MRMesh/MRPolylineRelax.cpp
@@ -0,0 +1,130 @@
+#include "MRPolylineRelax.h"
+#include "MRBitSetParallelFor.h"
+#include "MRPolyline.h"
+#include "MRTimer.h"
+#include "MRVector2.h"
+#include "MRWriter.h"
+
+namespace MR
+{
+
+template<typename V>
+bool relax( Polyline<V> &polyline, const RelaxParams &params, ProgressCallback cb )
+{
+    if ( params.iterations <= 0 )
+        return true;
+
+    MR_TIMER
+    MR_WRITER(polyline)
+
+    Vector<V, VertId> newPoints;
+    const auto& zone = polyline.topology.getVertIds( params.region );
+
+    bool keepGoing = true;
+    for ( int i = 0; i < params.iterations; ++i )
+    {
+        ProgressCallback internalCb;
+        if ( cb )
+        {
+            internalCb = [&]( float p )
+            {
+                return cb(( float( i ) + p ) / float( params.iterations ));
+            };
+        }
+
+        newPoints = polyline.points;
+        keepGoing = BitSetParallelFor( zone, [&]( VertId v )
+        {
+            auto e0 = polyline.topology.edgeWithOrg( v );
+            assert( !polyline.topology.isLoneEdge( e0 ) );
+            auto e1 = polyline.topology.next( e0 );
+            if ( e0 == e1 )
+                return;
+
+            auto mp = ( polyline.destPnt( e0 ) + polyline.destPnt( e1 ) ) / 2.f;
+
+            auto& np = newPoints[v];
+            auto pushForce = params.force * ( mp - np );
+            np += pushForce;
+        }, internalCb );
+        polyline.points.swap( newPoints );
+        if ( !keepGoing )
+            break;
+    }
+    return keepGoing;
+}
+
+template<typename V>
+bool relaxKeepArea( Polyline<V> &polyline, const RelaxParams &params, ProgressCallback cb )
+{
+    if ( params.iterations <= 0 )
+        return true;
+
+    MR_TIMER
+    MR_WRITER(polyline)
+
+    Vector<V, VertId> newPoints;
+    const auto& zone = polyline.topology.getVertIds( params.region );
+    std::vector<V> vertPushForces( zone.size() );
+
+    bool keepGoing = true;
+    for ( int i = 0; i < params.iterations; ++i )
+    {
+        ProgressCallback internalCb1, internalCb2;
+        if ( cb )
+        {
+            internalCb1 = [&] ( float p )
+            {
+                return cb( ( float( i ) + p * 0.5f ) / float( params.iterations ) );
+            };
+            internalCb2 = [&] ( float p )
+            {
+                return cb( ( float( i ) + p * 0.5f + 0.5f ) / float( params.iterations ) );
+            };
+        }
+
+        keepGoing = BitSetParallelFor( zone, [&]( VertId v )
+        {
+            auto e0 = polyline.topology.edgeWithOrg( v );
+            assert( !polyline.topology.isLoneEdge( e0 ) );
+            auto e1 = polyline.topology.next( e0 );
+            if ( e0 == e1 )
+                return;
+
+            auto mp = ( polyline.destPnt( e0 ) + polyline.destPnt( e1 ) ) / 2.f;
+
+            vertPushForces[v] = params.force * ( mp - polyline.points[v] );
+        }, internalCb1 );
+        if ( !keepGoing )
+            break;
+
+        newPoints = polyline.points;
+        keepGoing = BitSetParallelFor( zone, [&]( VertId v )
+        {
+            auto e0 = polyline.topology.edgeWithOrg( v );
+            assert( !polyline.topology.isLoneEdge( e0 ) );
+            auto e1 = polyline.topology.next( e0 );
+            if ( e0 == e1 )
+                return;
+
+            auto& np = newPoints[v];
+            np += vertPushForces[v];
+            auto modifier = 1.0f / 2.0f;
+            np -= ( vertPushForces[polyline.topology.dest( e0 )] * modifier );
+            np -= ( vertPushForces[polyline.topology.dest( e1 )] * modifier );
+        }, internalCb2 );
+        polyline.points.swap( newPoints );
+        if ( !keepGoing )
+            break;
+    }
+
+    return keepGoing;
+}
+
+template bool relax<>( Polyline2& polyline, const RelaxParams& params, ProgressCallback cb );
+template bool relax<>( Polyline3& polyline, const RelaxParams& params, ProgressCallback cb );
+
+template bool relaxKeepArea<>( Polyline2 &polyline, const RelaxParams &params, ProgressCallback cb );
+template bool relaxKeepArea<>( Polyline3 &polyline, const RelaxParams &params, ProgressCallback cb );
+
+} // namespace MR
\ No newline at end of file
diff --git a/source/MRMesh/MRPolylineRelax.h b/source/MRMesh/MRPolylineRelax.h
new file mode 100644
index 000000000000..d182433f96c4
--- /dev/null
+++ b/source/MRMesh/MRPolylineRelax.h
@@ -0,0 +1,25 @@
+#pragma once
+#include "MRMeshFwd.h"
+#include "MRProgressCallback.h"
+#include "MRRelaxParams.h"
+
+namespace MR
+{
+
+/// \addtogroup PolylineGroup
+/// \{
+
+/// applies given number of relaxation iterations to the whole polyline ( or some region if it is specified )
+/// \return true if was finished successfully, false if was interrupted by progress callback
+template<typename V>
+MRMESH_API bool relax( Polyline<V>& polyline, const RelaxParams& params = {}, ProgressCallback cb = {} );
+
+/// applies given number of relaxation iterations to the whole polyline ( or some region if it is specified )
+/// do not really keeps area but tries hard
+/// \return true if was finished successfully, false if was interrupted by progress callback
+template<typename V>
+MRMESH_API bool relaxKeepArea( Polyline<V>& polyline, const RelaxParams& params = {}, ProgressCallback cb = {} );
+
+/// \}
+
+} // namespace MR
diff --git a/source/MRMesh/MRRelaxParams.h b/source/MRMesh/MRRelaxParams.h
new file mode 100644
index 000000000000..e3a764156901
--- /dev/null
+++ b/source/MRMesh/MRRelaxParams.h
@@ -0,0 +1,23 @@
+#pragma once
+#include "MRMeshFwd.h"
+
+namespace MR
+{
+
+struct RelaxParams
+{
+    /// number of iterations
+    int iterations{1};
+    /// region to relax
+    const VertBitSet *region{nullptr};
+    /// speed of relaxing, typical values (0.0, 0.5]
+    float force{0.5f};
+};
+
+enum class RelaxApproxType
+{
+    Planar,
+    Quadric,
+};
+
+} // namespace MR
\ No newline at end of file