How to resize an image with OnyxPDF
- Drop your images into the tool.
- Set the target width/height in pixels (aspect ratio locked by default), or a percentage, or pick a social preset.
- Click “Resize Images”.
- Download the resized images.
Why do it in your browser instead of uploading?
- Presets for the sizes people actually need — no Googling “Instagram portrait dimensions” ever again.
- Aspect lock on by default, so faces never stretch.
- Batch resizing with no upload and no per-session caps.
- Before/after sizes shown for every file.
Good to know (honest limits)
- Enlarging a small image cannot invent detail — a 200 px photo stretched to 1280 px will look soft. The tool resizes honestly; it does not fake “AI upscale”.
- EXIF orientation is honoured on load; the output is a fresh encode, so camera metadata is not carried over.
Frequently asked questions
What size is a YouTube thumbnail / Instagram post?
YouTube thumbnail 1280×720; Instagram post 1080×1080, portrait 1080×1350, story 1080×1920; Facebook cover 1640×924; WhatsApp DP 640×640. All are one-tap presets in the tool.
Can I resize many images at once?
Yes — drop a batch and every image is resized with the same settings.
Will resizing keep my image sharp?
Downscaling stays sharp. Upscaling beyond the original size softens the image — no honest tool can add detail that was never captured.
Are my photos uploaded?
No. Resizing happens in your browser.