diff --git a/include/flatbuffers/verifier.h b/include/flatbuffers/verifier.h
new file mode 100644
index 0000000..4512d45
--- /dev/null
+++ b/include/flatbuffers/verifier.h
@@ -0,0 +1,283 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_VERIFIER_H_
+#define FLATBUFFERS_VERIFIER_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/util.h"
+#include "flatbuffers/vector.h"
+
+namespace flatbuffers {
+
+// Helper class to verify the integrity of a FlatBuffer
+class Verifier FLATBUFFERS_FINAL_CLASS {
+ public:
+  Verifier(const uint8_t *buf, size_t buf_len, uoffset_t _max_depth = 64,
+           uoffset_t _max_tables = 1000000, bool _check_alignment = true)
+      : buf_(buf),
+        size_(buf_len),
+        depth_(0),
+        max_depth_(_max_depth),
+        num_tables_(0),
+        max_tables_(_max_tables),
+        upper_bound_(0),
+        check_alignment_(_check_alignment),
+        flex_reuse_tracker_(nullptr) {
+    FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE);
+  }
+
+  // Central location where any verification failures register.
+  bool Check(bool ok) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_DEBUG_VERIFICATION_FAILURE
+      FLATBUFFERS_ASSERT(ok);
+    #endif
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      if (!ok)
+        upper_bound_ = 0;
+    #endif
+    // clang-format on
+    return ok;
+  }
+
+  // Verify any range within the buffer.
+  bool Verify(size_t elem, size_t elem_len) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      auto upper_bound = elem + elem_len;
+      if (upper_bound_ < upper_bound)
+        upper_bound_ =  upper_bound;
+    #endif
+    // clang-format on
+    return Check(elem_len < size_ && elem <= size_ - elem_len);
+  }
+
+  bool VerifyAlignment(size_t elem, size_t align) const {
+    return Check((elem & (align - 1)) == 0 || !check_alignment_);
+  }
+
+  // Verify a range indicated by sizeof(T).
+  template<typename T> bool Verify(size_t elem) const {
+    return VerifyAlignment(elem, sizeof(T)) && Verify(elem, sizeof(T));
+  }
+
+  bool VerifyFromPointer(const uint8_t *p, size_t len) {
+    auto o = static_cast<size_t>(p - buf_);
+    return Verify(o, len);
+  }
+
+  // Verify relative to a known-good base pointer.
+  bool VerifyFieldStruct(const uint8_t *base, voffset_t elem_off,
+                         size_t elem_len, size_t align) const {
+    auto f = static_cast<size_t>(base - buf_) + elem_off;
+    return VerifyAlignment(f, align) && Verify(f, elem_len);
+  }
+
+  template<typename T>
+  bool VerifyField(const uint8_t *base, voffset_t elem_off,
+                   size_t align) const {
+    auto f = static_cast<size_t>(base - buf_) + elem_off;
+    return VerifyAlignment(f, align) && Verify(f, sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a table type.
+  template<typename T> bool VerifyTable(const T *table) {
+    return !table || table->Verify(*this);
+  }
+
+  // Verify a pointer (may be NULL) of any vector type.
+  template<typename T> bool VerifyVector(const Vector<T> *vec) const {
+    return !vec || VerifyVectorOrString(reinterpret_cast<const uint8_t *>(vec),
+                                        sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a vector to struct.
+  template<typename T> bool VerifyVector(const Vector<const T *> *vec) const {
+    return VerifyVector(reinterpret_cast<const Vector<T> *>(vec));
+  }
+
+  // Verify a pointer (may be NULL) to string.
+  bool VerifyString(const String *str) const {
+    size_t end;
+    return !str || (VerifyVectorOrString(reinterpret_cast<const uint8_t *>(str),
+                                         1, &end) &&
+                    Verify(end, 1) &&           // Must have terminator
+                    Check(buf_[end] == '\0'));  // Terminating byte must be 0.
+  }
+
+  // Common code between vectors and strings.
+  bool VerifyVectorOrString(const uint8_t *vec, size_t elem_size,
+                            size_t *end = nullptr) const {
+    auto veco = static_cast<size_t>(vec - buf_);
+    // Check we can read the size field.
+    if (!Verify<uoffset_t>(veco)) return false;
+    // Check the whole array. If this is a string, the byte past the array
+    // must be 0.
+    auto size = ReadScalar<uoffset_t>(vec);
+    auto max_elems = FLATBUFFERS_MAX_BUFFER_SIZE / elem_size;
+    if (!Check(size < max_elems))
+      return false;  // Protect against byte_size overflowing.
+    auto byte_size = sizeof(size) + elem_size * size;
+    if (end) *end = veco + byte_size;
+    return Verify(veco, byte_size);
+  }
+
+  // Special case for string contents, after the above has been called.
+  bool VerifyVectorOfStrings(const Vector<Offset<String>> *vec) const {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!VerifyString(vec->Get(i))) return false;
+      }
+    }
+    return true;
+  }
+
+  // Special case for table contents, after the above has been called.
+  template<typename T> bool VerifyVectorOfTables(const Vector<Offset<T>> *vec) {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!vec->Get(i)->Verify(*this)) return false;
+      }
+    }
+    return true;
+  }
+
+  __supress_ubsan__("unsigned-integer-overflow") bool VerifyTableStart(
+      const uint8_t *table) {
+    // Check the vtable offset.
+    auto tableo = static_cast<size_t>(table - buf_);
+    if (!Verify<soffset_t>(tableo)) return false;
+    // This offset may be signed, but doing the subtraction unsigned always
+    // gives the result we want.
+    auto vtableo = tableo - static_cast<size_t>(ReadScalar<soffset_t>(table));
+    // Check the vtable size field, then check vtable fits in its entirety.
+    return VerifyComplexity() && Verify<voffset_t>(vtableo) &&
+           VerifyAlignment(ReadScalar<voffset_t>(buf_ + vtableo),
+                           sizeof(voffset_t)) &&
+           Verify(vtableo, ReadScalar<voffset_t>(buf_ + vtableo));
+  }
+
+  template<typename T>
+  bool VerifyBufferFromStart(const char *identifier, size_t start) {
+    if (identifier && !Check((size_ >= 2 * sizeof(flatbuffers::uoffset_t) &&
+                              BufferHasIdentifier(buf_ + start, identifier)))) {
+      return false;
+    }
+
+    // Call T::Verify, which must be in the generated code for this type.
+    auto o = VerifyOffset(start);
+    return o && reinterpret_cast<const T *>(buf_ + start + o)->Verify(*this)
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+           && GetComputedSize()
+    #endif
+        ;
+    // clang-format on
+  }
+
+  template<typename T>
+  bool VerifyNestedFlatBuffer(const Vector<uint8_t> *buf,
+                              const char *identifier) {
+    if (!buf) return true;
+    Verifier nested_verifier(buf->data(), buf->size());
+    return nested_verifier.VerifyBuffer<T>(identifier);
+  }
+
+  // Verify this whole buffer, starting with root type T.
+  template<typename T> bool VerifyBuffer() { return VerifyBuffer<T>(nullptr); }
+
+  template<typename T> bool VerifyBuffer(const char *identifier) {
+    return VerifyBufferFromStart<T>(identifier, 0);
+  }
+
+  template<typename T> bool VerifySizePrefixedBuffer(const char *identifier) {
+    return Verify<uoffset_t>(0U) &&
+           ReadScalar<uoffset_t>(buf_) == size_ - sizeof(uoffset_t) &&
+           VerifyBufferFromStart<T>(identifier, sizeof(uoffset_t));
+  }
+
+  uoffset_t VerifyOffset(size_t start) const {
+    if (!Verify<uoffset_t>(start)) return 0;
+    auto o = ReadScalar<uoffset_t>(buf_ + start);
+    // May not point to itself.
+    if (!Check(o != 0)) return 0;
+    // Can't wrap around / buffers are max 2GB.
+    if (!Check(static_cast<soffset_t>(o) >= 0)) return 0;
+    // Must be inside the buffer to create a pointer from it (pointer outside
+    // buffer is UB).
+    if (!Verify(start + o, 1)) return 0;
+    return o;
+  }
+
+  uoffset_t VerifyOffset(const uint8_t *base, voffset_t start) const {
+    return VerifyOffset(static_cast<size_t>(base - buf_) + start);
+  }
+
+  // Called at the start of a table to increase counters measuring data
+  // structure depth and amount, and possibly bails out with false if
+  // limits set by the constructor have been hit. Needs to be balanced
+  // with EndTable().
+  bool VerifyComplexity() {
+    depth_++;
+    num_tables_++;
+    return Check(depth_ <= max_depth_ && num_tables_ <= max_tables_);
+  }
+
+  // Called at the end of a table to pop the depth count.
+  bool EndTable() {
+    depth_--;
+    return true;
+  }
+
+  // Returns the message size in bytes
+  size_t GetComputedSize() const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      uintptr_t size = upper_bound_;
+      // Align the size to uoffset_t
+      size = (size - 1 + sizeof(uoffset_t)) & ~(sizeof(uoffset_t) - 1);
+      return (size > size_) ?  0 : size;
+    #else
+      // Must turn on FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE for this to work.
+      (void)upper_bound_;
+      FLATBUFFERS_ASSERT(false);
+      return 0;
+    #endif
+    // clang-format on
+  }
+
+  std::vector<uint8_t> *GetFlexReuseTracker() { return flex_reuse_tracker_; }
+
+  void SetFlexReuseTracker(std::vector<uint8_t> *rt) {
+    flex_reuse_tracker_ = rt;
+  }
+
+ private:
+  const uint8_t *buf_;
+  size_t size_;
+  uoffset_t depth_;
+  uoffset_t max_depth_;
+  uoffset_t num_tables_;
+  uoffset_t max_tables_;
+  mutable size_t upper_bound_;
+  bool check_alignment_;
+  std::vector<uint8_t> *flex_reuse_tracker_;
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_VERIFIER_H_