Resize Video
Resize video to specific width and height
Configure
About this tool
Choose one supported file from your device (.mp4, .mov, .avi, .mkv, .webm). This workflow does not accept a source URL. Uploaded files are processed by SimplifyConvert's server-side media tools. Temporary working files are scheduled for cleanup after processing, while completed downloads use the site's download-result workflow.
Ready to process
Upload one supported file and start processing.
Fit a video into new pixel dimensions
Resize Video re-encodes the picture into a requested width and height and returns MP4. With aspect preservation enabled, the source fits inside the requested box without stretching; the actual output can be smaller than one requested dimension.
When dimensions need to change
- •Create a smaller review copy from a high-resolution source.
- •Fit footage within a platform maximum width and height.
- •Deliberately create exact dimensions when stretching is acceptable.
How to use this tool
- 1.Upload MP4, MOV, AVI, MKV, or WebM up to 500 MB.
- 2.Enter width from 160-7680 and height from 120-4320, then decide whether to preserve aspect ratio.
- 3.Resize and inspect dimensions, shape, small text, motion detail, audio, and file size.
Scaling and encoding behavior
- Aspect-preserving mode uses FFmpeg scale with force_original_aspect_ratio=decrease, fitting inside the requested box without padding.
- Aspect-preserving dimensions are adjusted down to even numbers when necessary; disabling it scales to the exact width and height and can distort the picture.
- Video is re-encoded at a 5000 kb/s target while the existing audio stream is copied into the MP4 output.
Example: fit 1920 × 1080 footage inside 1080 × 1080
With aspect ratio enabled, a 16:9 source fits inside the square box as approximately 1080 × 607 rather than stretching to a square. Disable preservation only if an exact 1080 × 1080 distorted frame is intentionally required.
Resolution is not recovered detail
- Upscaling increases pixel dimensions but cannot reconstruct detail absent from the source.
- A fixed 5000 kb/s video target does not guarantee smaller output; low-bitrate sources can become larger.
- Copied audio must be compatible with the MP4 container, and unusual streams can fail.
Resolve size or shape problems
- Output is not the exact box: aspect preservation fits inside it; disable the option only if stretching is acceptable.
- Output looks soft: avoid unnecessary upscaling or choose dimensions closer to the source.
- File grew: resizing and file-size compression are separate; compare Compress Video after choosing dimensions.
Continue the workflow
Return to Video tools, or continue with a complementary tool:
Learn how resolution, bitrate, codec, and frame rate interact
Questions about this specific tool
What does Keep Aspect Ratio do?
It fits the source inside the requested width and height without stretching. One output dimension can therefore be smaller than the entered box.
Will upscaling improve quality?
No. It creates more pixels through scaling but cannot recover missing source detail.
Does a lower resolution guarantee a smaller file?
No. The output also depends on duration, content, source encoding, and the fixed video bitrate used by this route.
What happens to audio?
The resize command copies the source audio stream rather than re-encoding it.