diff --git a/kitty/data-types.c b/kitty/data-types.c
index 65bf57ce3..fbf8308ab 100644
--- a/kitty/data-types.c
+++ b/kitty/data-types.c
@@ -89,6 +89,17 @@ pybase64_encode(PyObject UNUSED *self, PyObject *args) {
     return ans;
 }
 
+static PyObject*
+base64_encode_into(PyObject UNUSED *self, PyObject *args) {
+    int add_padding = 0;
+    RAII_PY_BUFFER(view); RAII_PY_BUFFER(output);
+    if (!PyArg_ParseTuple(args, "s*w*|i", &view, &add_padding)) return NULL;
+    size_t sz = required_buffer_size_for_base64_encode(view.len);
+    if (output.len < (ssize_t)sz) { PyErr_SetString(PyExc_TypeError, "output buffer too small"); return NULL; }
+    base64_encode8(view.buf, view.len, output.buf, &sz, add_padding);
+    return PyLong_FromSize_t(sz);
+}
+
 static PyObject*
 pybase64_decode(PyObject UNUSED *self, PyObject *args) {
     RAII_PY_BUFFER(view);
@@ -105,6 +116,20 @@ pybase64_decode(PyObject UNUSED *self, PyObject *args) {
     return ans;
 }
 
+static PyObject*
+base64_decode_into(PyObject UNUSED *self, PyObject *args) {
+    RAII_PY_BUFFER(view); RAII_PY_BUFFER(output);
+    if (!PyArg_ParseTuple(args, "s*", &view, &output)) return NULL;
+    size_t sz = required_buffer_size_for_base64_decode(view.len);
+    if (output.len < (ssize_t)sz) { PyErr_SetString(PyExc_TypeError, "output buffer too small"); return NULL; }
+    if (!base64_decode8(view.buf, view.len, output.buf, &sz)) {
+        PyErr_SetString(PyExc_ValueError, "Invalid base64 input data");
+        return NULL;
+    }
+    return PyLong_FromSize_t(sz);
+}
+
+
 typedef struct StreamingBase64Decoder {
     PyObject_HEAD
     struct base64_state state;
@@ -560,7 +585,9 @@ static PyMethodDef module_methods[] = {
     {"close_tty", close_tty, METH_VARARGS, ""},
     {"set_iutf8_fd", (PyCFunction)pyset_iutf8, METH_VARARGS, ""},
     {"base64_encode", (PyCFunction)pybase64_encode, METH_VARARGS, ""},
+    {"base64_encode_into", (PyCFunction)base64_encode_into, METH_VARARGS, ""},
     {"base64_decode", (PyCFunction)pybase64_decode, METH_VARARGS, ""},
+    {"base64_decode_into", (PyCFunction)base64_decode_into, METH_VARARGS, ""},
     {"thread_write", (PyCFunction)cm_thread_write, METH_VARARGS, ""},
     {"redirect_std_streams", (PyCFunction)redirect_std_streams, METH_VARARGS, ""},
     {"locale_is_valid", (PyCFunction)locale_is_valid, METH_VARARGS, ""},
diff --git a/kitty/fast_data_types.pyi b/kitty/fast_data_types.pyi
index bfd5c7e19..954995878 100644
--- a/kitty/fast_data_types.pyi
+++ b/kitty/fast_data_types.pyi
@@ -1682,8 +1682,10 @@ def expand_ansi_c_escapes(test: str) -> str: ...
 def update_tab_bar_edge_colors(os_window_id: int) -> bool: ...
 def mask_kitty_signals_process_wide() -> None: ...
 def is_modifier_key(key: int) -> bool: ...
-def base64_encode(src: Union[bytes,str], add_padding: bool = False) -> bytes: ...
-def base64_decode(src: Union[bytes,str]) -> bytes: ...
+def base64_encode(src: ReadableBuffer, add_padding: bool = False) -> bytes: ...
+def base64_encode_into(src: ReadableBuffer, output: WriteableBuffer, add_padding: bool = False) -> int: ...
+def base64_decode(src: ReadableBuffer) -> bytes: ...
+def base64_decode_into(src: ReadableBuffer, output: WriteableBuffer) -> int: ...
 def cocoa_recreate_global_menu() -> None: ...
 def cocoa_clear_global_shortcuts() -> None: ...
 def update_pointer_shape(os_window_id: int) -> None: ...