Browser Image Resizer
Convert JPEG, PNG or static WebP still images to PNG with bounded browser work and verified output bytes.
Bounded local intake
Add still raster images
Binary signatures and dimensions are checked before files enter the queue. Animated, multi-image, truncated, and structurally ambiguous inputs are rejected.
Accepted signatures: JPEG, PNG, WEBP · up to 30 files within one decoded-work budget · paste with Ctrl/Cmd+V
Verified destination
Output contract
Lossless PNG. Alpha is retained when the browser decoder exposes it.
This route applies maximum dimensions while preserving aspect ratio and never upscales. Leave one side blank to constrain only the other.
Bounded queue
0 files checked
No file bytes are retained yet. Add files above to run signature, dimension, and browser-decode checks.
Metadata outcome
- Browser-decoded orientation is rendered into output pixels; manual orientation controls are not provided here.
- EXIF, GPS, capture date, and source metadata are stripped by canvas re-encoding.
- ICC profiles are not preserved; browser color conversion may change wide-gamut or HDR sources to SDR.
- Alpha is retained only when both decoder and output support it.
Local boundary
Selecting a file gives this tab temporary local access to its bytes. Conversion code runs in the browser and this workflow does not send file bytes, names, content, or precise dimensions to analytics. Ordinary page requests and coarse product events still use the network. Files and object URLs remain until you remove them, clear the workbench, or close the tab.
Raster work is limited to one or two concurrent browser jobs. Some canvas work can still occupy the main thread; cancellation is cooperative and an in-flight browser decode may finish before its result is discarded.
Instructions
How this conversion works
- 01Select .jpg or .jpeg or .png or .webp files. The browser checks type and total work before processing.
- 02Review the PNG controls and start conversion. Unsupported browser decoders are reported as a retryable file error.
- 03Download output only after its MIME, signature and extension contract passes.
Limitations
Read before processing
- Files are processed in browser memory. Site assets and coarse analytics still use ordinary network requests; file bytes and names are excluded from events.
- Canvas-based output does not preserve source EXIF, GPS, capture date or embedded ICC profiles.
- A download is exposed only when the result reports PNG bytes that agree with its MIME and extension.
Why people resize images
Modern phone cameras produce images several times larger than anything they will be displayed at, so most resizing is about matching the picture to where it is actually going: a maximum dimension for a website, a profile photo, a forum or marketplace limit, or an attachment that has to fit under a size cap. Reducing dimensions cuts file size much more aggressively than compression alone, because it removes pixels rather than approximating them. Resizing downwards is safe; enlarging is not, since the detail to fill the extra pixels does not exist, which is why this tool never upscales.
How to convert JPEG, PNG or static WebP to PNG
1. Add JPEG, PNG or static WebP files for bounded signature and decoder checks.
2. Review PNG controls and the decoded-work estimate.
3. Start the cancellable queue.
4. Download files only after output validation passes.
Capability boundary
Maximum dimensions preserve aspect ratio and never upscale. Source metadata and color profiles are not retained.
Questions
Frequently asked questions
Will resizing distort my image?
No. You give a maximum width and height, and the image is scaled to fit inside that box with its aspect ratio preserved. It is never stretched to match both numbers exactly.
Can I make an image larger?
Not here. Upscaling has to invent pixels that were never captured, and the result is a softer, larger file rather than a more detailed picture. This tool only reduces dimensions, so a maximum bigger than the original leaves the image untouched.
How is PNG output checked?
The browser encoder must return the expected MIME and binary signature. The result is decoded again and its dimensions are checked before download.
What happens to source metadata?
Canvas re-encoding strips EXIF, GPS and capture date. ICC profiles are not preserved, and HDR or wide-gamut input may be converted to SDR.
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