Compress Video with FFmpeg and H.265/HEVC: Complete Guide

H.265/HEVC delivers the same visual quality as H.264 in files 40–50 % smaller. FFmpeg with libx265 is the most powerful way to leverage this codec from the command line.

H.264 vs H.265 vs AV1: quick comparison

Basic MP4 → H.265 conversion

ffmpeg -i input.mp4 -c:v libx265 -c:a copy output_h265.mp4
ffmpeg -i input.mp4 -c:v libx265 -crf 28 -c:a copy output.mp4
ffmpeg -i input.mp4 -c:v libx265 -crf 24 -preset medium -c:a aac -b:a 128k output.mp4

CRF quality guide

Presets

# ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow
ffmpeg -i input.mp4 -c:v libx265 -crf 28 -preset medium output.mp4
ffmpeg -i input.mp4 -c:v libx265 -crf 28 -preset slow output.mp4

Hardware acceleration

# NVIDIA NVENC
ffmpeg -i input.mp4 -c:v hevc_nvenc -cq 28 -preset p4 output_nvenc.mp4

# Intel Quick Sync
ffmpeg -i input.mp4 -c:v hevc_qsv -global_quality 28 output_qsv.mp4

# Apple VideoToolbox (M1/M2/M3)
ffmpeg -i input.mp4 -c:v hevc_videotoolbox -q:v 60 output_mac.mp4

# Check available encoders
ffmpeg -encoders 2>/dev/null | grep hevc

Batch convert (Bash)

#!/bin/bash
mkdir -p output_h265

for f in *.mp4; do
    name="${f%.mp4}"
    ffmpeg -i "$f" -c:v libx265 -crf 26 -preset medium \
        -c:a aac -b:a 128k -movflags +faststart \
        "output_h265/${name}_h265.mp4" -y
done

Python with subprocess

import subprocess
from pathlib import Path

def compress_h265(input_path, output_path, crf=26, preset='medium'):
    cmd = ['ffmpeg', '-i', str(input_path),
           '-c:v', 'libx265', '-crf', str(crf), '-preset', preset,
           '-c:a', 'aac', '-b:a', '128k', '-movflags', '+faststart',
           str(output_path), '-y']
    result = subprocess.run(cmd, capture_output=True, text=True)
    return result.returncode == 0

for video in sorted(Path('videos/').glob('*.mp4')):
    output = Path('h265') / video.name
    output.parent.mkdir(exist_ok=True)
    ok = compress_h265(video, output)
    if ok:
        orig = video.stat().st_size / 1024 / 1024
        comp = output.stat().st_size / 1024 / 1024
        print(f"OK: {video.name} → {orig:.1f}MB → {comp:.1f}MB ({(1-comp/orig)*100:.0f}% smaller)")