Guide #6

Resize video with FFmpeg

Resizing is common for web playback, previews, and platform exports. The important parts are aspect ratio, even dimensions, and the final codec.

Copy + paste this:

Resize while preserving aspect ratio.

ffmpeg -i input -vf scale=-2:720 -c:v libx264 -crf 23 -c:a copy 720p.mp4

When this is the right tool

Start by checking whether this operation matches the job you actually need.

Use this when

3 Good fit

You need 1080p, 720p, or mobile-size versions.
You want smaller files and do not need full source resolution.
A platform requires a specific output size.

Be careful when

2 Watch out

You are upscaling low-quality input and expecting real detail.
You crop without checking important content near the edges.

Examples

Use these as starting points, then tune quality, size, and timing on real input files.

Scale to 720p

Resize while preserving aspect ratio.

ffmpeg -i input -vf scale=-2:720 -c:v libx264 -crf 23 -c:a copy 720p.mp4

Command breakdown

input input: Reads this input file.
-vf scale=-2:720: Applies a video filter chain.
-c:v libx264: Sets the video codec.
-crf 23: Controls visual quality. Lower values make larger, higher-quality files.
-c:a copy: Copies streams without re-encoding.
output 720p.mp4: Writes this output file.

Fit into 1080p canvas

Preserve content and pad to exact 1920x1080.

ffmpeg -i input -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -crf 23 -c:a aac fitted.mp4

Command breakdown

input input: Reads this input file.
-vf scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2: Applies a video filter chain.
-c:v libx264: Sets the video codec.
-crf 23: Controls visual quality. Lower values make larger, higher-quality files.
-c:a aac: Sets the audio codec.
output fitted.mp4: Writes this output file.

Helpful tips

These details prevent most bad outputs and confusing FFmpeg results.

Use -2 for even dimensions

Many codecs need dimensions divisible by 2. `scale=-2:720` keeps aspect ratio and chooses a valid width.

Crop changes content

Cropping fills a target aspect ratio but removes pixels from the edges.

Padding preserves content

Padding fits a target canvas without cutting the image, but adds bars.

Related guides

Useful next steps when this operation is part of a larger workflow.

Compress video with FFmpeg

Learn practical FFmpeg video compression using CRF, presets, bitrate caps, and web-safe MP4 settings.

Create video thumbnails with FFmpeg

Learn how to create thumbnails, choose useful timestamps, and generate contact sheets with FFmpeg.

Convert video format with FFmpeg

Learn how to convert MOV, MKV, WebM, and AVI files to MP4 with FFmpeg, when to copy streams, and when to re-encode.

Need to run this at scale?

Run the same FFmpeg commands through a hosted API.

Keep the FFmpeg command surface. Very Good FFmpeg handles machines, logs, long jobs, outputs, and webhooks.

Try free Read API docs

Guide #6

Resize video with FFmpeg

Resizing is common for web playback, previews, and platform exports. The important parts are aspect ratio, even dimensions, and the final codec.

Copy + paste this:

Resize while preserving aspect ratio.

ffmpeg -i input -vf scale=-2:720 -c:v libx264 -crf 23 -c:a copy 720p.mp4

When this is the right tool

Start by checking whether this operation matches the job you actually need.

Use this when

3 Good fit

You need 1080p, 720p, or mobile-size versions.
You want smaller files and do not need full source resolution.
A platform requires a specific output size.

Be careful when

2 Watch out

You are upscaling low-quality input and expecting real detail.
You crop without checking important content near the edges.

Examples

Use these as starting points, then tune quality, size, and timing on real input files.

Scale to 720p

Resize while preserving aspect ratio.

ffmpeg -i input -vf scale=-2:720 -c:v libx264 -crf 23 -c:a copy 720p.mp4

Command breakdown

input input: Reads this input file.
-vf scale=-2:720: Applies a video filter chain.
-c:v libx264: Sets the video codec.
-crf 23: Controls visual quality. Lower values make larger, higher-quality files.
-c:a copy: Copies streams without re-encoding.
output 720p.mp4: Writes this output file.

Fit into 1080p canvas

Preserve content and pad to exact 1920x1080.

ffmpeg -i input -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -crf 23 -c:a aac fitted.mp4

Command breakdown

input input: Reads this input file.
-vf scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2: Applies a video filter chain.
-c:v libx264: Sets the video codec.
-crf 23: Controls visual quality. Lower values make larger, higher-quality files.
-c:a aac: Sets the audio codec.
output fitted.mp4: Writes this output file.

Helpful tips

These details prevent most bad outputs and confusing FFmpeg results.

Use -2 for even dimensions

Many codecs need dimensions divisible by 2. `scale=-2:720` keeps aspect ratio and chooses a valid width.

Crop changes content

Cropping fills a target aspect ratio but removes pixels from the edges.

Padding preserves content

Padding fits a target canvas without cutting the image, but adds bars.

Related guides

Useful next steps when this operation is part of a larger workflow.

Compress video with FFmpeg

Learn practical FFmpeg video compression using CRF, presets, bitrate caps, and web-safe MP4 settings.

Create video thumbnails with FFmpeg

Learn how to create thumbnails, choose useful timestamps, and generate contact sheets with FFmpeg.

Convert video format with FFmpeg

Learn how to convert MOV, MKV, WebM, and AVI files to MP4 with FFmpeg, when to copy streams, and when to re-encode.

Need to run this at scale?

Run the same FFmpeg commands through a hosted API.

Keep the FFmpeg command surface. Very Good FFmpeg handles machines, logs, long jobs, outputs, and webhooks.

Try free Read API docs