diff --git a/toolbox/Android.mk b/toolbox/Android.mk
index d6ead1a..aa755ed 100644
--- a/toolbox/Android.mk
+++ b/toolbox/Android.mk
@@ -95,3 +95,13 @@
 LOCAL_MODULE := grep
 LOCAL_POST_INSTALL_CMD := $(hide) $(foreach t,egrep fgrep,ln -sf grep $(TARGET_OUT)/bin/$(t);)
 include $(BUILD_EXECUTABLE)
+
+
+# We build gzip separately, so it can provide gunzip and zcat too.
+include $(CLEAR_VARS)
+LOCAL_MODULE := gzip
+LOCAL_SRC_FILES := gzip.c
+LOCAL_CFLAGS += -Wall -Werror
+LOCAL_SHARED_LIBRARIES += libz
+LOCAL_POST_INSTALL_CMD := $(hide) $(foreach t,gunzip zcat,ln -sf gzip $(TARGET_OUT)/bin/$(t);)
+include $(BUILD_EXECUTABLE)
diff --git a/toolbox/gzip.c b/toolbox/gzip.c
new file mode 100644
index 0000000..62c4518
--- /dev/null
+++ b/toolbox/gzip.c
@@ -0,0 +1,261 @@
+/* gzip.c - gzip/gunzip/zcat tools for gzip data
+ *
+ * Copyright 2017 The Android Open Source Project
+ *
+ * GZIP RFC: http://www.ietf.org/rfc/rfc1952.txt
+
+TODO: port to toybox.
+
+*/
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <zlib.h>
+
+// toybox-style flags/globals.
+#define FLAG_c 1
+#define FLAG_d 2
+#define FLAG_f 4
+#define FLAG_k 8
+static struct {
+  int optflags;
+} toys;
+static struct {
+  int level;
+} TT;
+
+static void xstat(const char *path, struct stat *sb)
+{
+  if (stat(path, sb)) error(1, errno, "stat %s", path);
+}
+
+static void fix_time(const char *path, struct stat *sb)
+{
+  struct timespec times[] = { sb->st_atim, sb->st_mtim };
+
+  if (utimensat(AT_FDCWD, path, times, 0)) error(1, errno, "utimes");
+}
+
+static FILE *xfdopen(const char *name, int flags, mode_t open_mode,
+    const char *mode)
+{
+  FILE *fp;
+  int fd;
+
+  if (!strcmp(name, "-")) fd = dup((*mode == 'r') ? 0 : 1);
+  else fd = open(name, flags, open_mode);
+
+  if (fd == -1) error(1, errno, "open %s (%s)", name, mode);
+  fp = fdopen(fd, mode);
+  if (fp == NULL) error(1, errno, "fopen %s (%s)", name, mode);
+  return fp;
+}
+
+static gzFile xgzopen(const char *name, int flags, mode_t open_mode,
+    const char *mode)
+{
+  gzFile f;
+  int fd;
+
+  if (!strcmp(name, "-")) fd = dup((*mode == 'r') ? 0 : 1);
+  else fd = open(name, flags, open_mode);
+
+  if (fd == -1) error(1, errno, "open %s (%s)", name, mode);
+  f = gzdopen(fd, mode);
+  if (f == NULL) error(1, errno, "gzdopen %s (%s)", name, mode);
+  return f;
+}
+
+static void gzfatal(gzFile f, char *what)
+{
+  int err;
+  const char *msg = gzerror(f, &err);
+
+  error(1, (err == Z_ERRNO) ? errno : 0, "%s: %s", what, msg);
+}
+
+static void gunzip(char *arg)
+{
+  struct stat sb;
+  char buf[BUFSIZ];
+  int len, both_files;
+  char *in_name, *out_name;
+  gzFile in;
+  FILE *out;
+
+  // "gunzip x.gz" will decompress "x.gz" to "x".
+  len = strlen(arg);
+  if (len > 3 && !strcmp(arg+len-3, ".gz")) {
+    in_name = strdup(arg);
+    out_name = strdup(arg);
+    out_name[len-3] = '\0';
+  } else if (!strcmp(arg, "-")) {
+    // "-" means stdin; assume output to stdout.
+    // TODO: require -f to read compressed data from tty?
+    in_name = strdup("-");
+    out_name = strdup("-");
+  } else error(1, 0, "unknown suffix");
+
+  if (toys.optflags&FLAG_c) {
+    free(out_name);
+    out_name = strdup("-");
+  }
+
+  both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
+  if (both_files) xstat(in_name, &sb);
+
+  in = xgzopen(in_name, O_RDONLY, 0, "r");
+  out = xfdopen(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
+      both_files?sb.st_mode:0666, "w");
+
+  while ((len = gzread(in, buf, sizeof(buf))) > 0) {
+    if (fwrite(buf, 1, len, out) != (size_t) len) error(1, errno, "fwrite");
+  }
+  if (len < 0) gzfatal(in, "gzread");
+  if (fclose(out)) error(1, errno, "fclose");
+  if (gzclose(in) != Z_OK) error(1, 0, "gzclose");
+
+  if (both_files) fix_time(out_name, &sb);
+  if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
+  free(in_name);
+  free(out_name);
+}
+
+static void gzip(char *in_name)
+{
+  char buf[BUFSIZ];
+  size_t len;
+  char *out_name;
+  FILE *in;
+  gzFile out;
+  struct stat sb;
+  int both_files;
+
+  if (toys.optflags&FLAG_c) {
+    out_name = strdup("-");
+  } else {
+    if (asprintf(&out_name, "%s.gz", in_name) == -1) {
+      error(1, errno, "asprintf");
+    }
+  }
+
+  both_files = strcmp(in_name, "-") && strcmp(out_name, "-");
+  if (both_files) xstat(in_name, &sb);
+
+  snprintf(buf, sizeof(buf), "w%d", TT.level);
+  in = xfdopen(in_name, O_RDONLY, 0, "r");
+  out = xgzopen(out_name, O_CREAT|O_WRONLY|((toys.optflags&FLAG_f)?0:O_EXCL),
+      both_files?sb.st_mode:0, buf);
+
+  while ((len = fread(buf, 1, sizeof(buf), in)) > 0) {
+    if (gzwrite(out, buf, len) != (int) len) gzfatal(out, "gzwrite");
+  }
+  if (ferror(in)) error(1, errno, "fread");
+  if (fclose(in)) error(1, errno, "fclose");
+  if (gzclose(out) != Z_OK) error(1, 0, "gzclose");
+
+  if (both_files) fix_time(out_name, &sb);
+  if (!(toys.optflags&(FLAG_c|FLAG_k))) unlink(in_name);
+  free(out_name);
+}
+
+static void do_file(char *arg)
+{
+  if (toys.optflags&FLAG_d) gunzip(arg);
+  else gzip(arg);
+}
+
+static void usage()
+{
+  char *cmd = basename(getprogname());
+
+  printf("usage: %s [-c] [-d] [-f] [-#] [FILE...]\n", cmd);
+  printf("\n");
+  if (!strcmp(cmd, "zcat")) {
+    printf("Decompress files to stdout. Like `gzip -dc`.\n");
+    printf("\n");
+    printf("-c\tOutput to stdout\n");
+    printf("-f\tForce: allow read from tty\n");
+  } else if (!strcmp(cmd, "gunzip")) {
+    printf("Decompress files. With no files, decompresses stdin to stdout.\n");
+    printf("On success, the input files are removed and replaced by new\n");
+    printf("files without the .gz suffix.\n");
+    printf("\n");
+    printf("-c\tOutput to stdout\n");
+    printf("-f\tForce: allow read from tty\n");
+    printf("-k\tKeep input files (don't remove)\n");
+  } else { // gzip
+    printf("Compress files. With no files, compresses stdin to stdout.\n");
+    printf("On success, the input files are removed and replaced by new\n");
+    printf("files with the .gz suffix.\n");
+    printf("\n");
+    printf("-c\tOutput to stdout\n");
+    printf("-d\tDecompress (act as gunzip)\n");
+    printf("-f\tForce: allow overwrite of output file\n");
+    printf("-k\tKeep input files (don't remove)\n");
+    printf("-#\tCompression level 1-9 (1:fastest, 6:default, 9:best)\n");
+  }
+  printf("\n");
+}
+
+int main(int argc, char *argv[])
+{
+  char *cmd = basename(argv[0]);
+  int opt_ch;
+
+  toys.optflags = 0;
+  TT.level = 6;
+
+  if (!strcmp(cmd, "gunzip")) {
+    // gunzip == gzip -d
+    toys.optflags = FLAG_d;
+  } else if (!strcmp(cmd, "zcat")) {
+    // zcat == gzip -dc
+    toys.optflags = (FLAG_c|FLAG_d);
+  }
+
+  while ((opt_ch = getopt(argc, argv, "cdfhk123456789")) != -1) {
+    switch (opt_ch) {
+    case 'c': toys.optflags |= FLAG_c; break;
+    case 'd': toys.optflags |= FLAG_d; break;
+    case 'f': toys.optflags |= FLAG_f; break;
+    case 'k': toys.optflags |= FLAG_k; break;
+
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+      TT.level = opt_ch - '0';
+      break;
+
+    default:
+      usage();
+      return 1;
+    }
+  }
+
+  if (optind == argc) {
+    // With no arguments, we go from stdin to stdout.
+    toys.optflags |= FLAG_c;
+    do_file("-");
+    return 0;
+  }
+
+  // Otherwise process each file in turn.
+  while (optind < argc) do_file(argv[optind++]);
+  return 0;
+}