Image Resizer
Drop JPG, PNG or WEBP files above, pick aspect-preserving scaling or an exact W×H canvas, and press Run all — every row shows before→after dimensions and size. Files never leave your browser.
Add files
Drop your images here
JPG · JPEG · PNG · WEBP · AVIF · BMP · up to 20MB each · multi-file supported
Presets
Presets only fill the free-size fields; press Run all to apply.
- Files added
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- Completed
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- Original total
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- Output total
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Add images and press Run all to get a result row per file.
No files added yet.
Everything runs locally through the browser Canvas API. Files never leave your device, and redrawing strips EXIF metadata such as GPS tags. The quality slider applies to JPG and WEBP output; PNG stays lossless.
ready to use.
- Visible firstKeep the input and result positions clear.
- Results firstPut the main number up front and keep the process secondary.
- Less to askNo sign-up or extra information before using the tool.
Choosing numbers before you resize images
"Make this image smaller" splits into two very different jobs: cutting kilobytes or cutting pixels. This tool handles the second. Knowing which constraint you actually face decides which tool you open first.
The notes below cover how ratio math works, how cm requirements translate to pixels at print resolution, and how to pick between JPG, PNG and WEBP output.
Resizing is not compressing
The resizer answers questions like “max 400 px”, the compressor answers “under 500 KB”. Shrinking dimensions also shrinks weight as a side effect, but forms enforce each rule separately — run the resizer first when both apply.
- Px requirement → resizer
- KB/MB requirement → compressor
- Both → resize, then compress
- Different files, different orders welcome
The math behind keep-ratio modes
Every ratio mode computes one scale factor — target ÷ current value of the chosen side — and applies it to width and height together. At 50%, both sides become exactly half; long-edge mode keys off whichever side is longer.
- % — uniform factor on both sides
- Width/height — opposite side computed
- Long edge — uses max(w,h)
- Rounding adds at most ±1 px
Stretch vs crop in exact mode
When source and target ratios differ, something has to give: Stretch warps the picture to fit every pixel, Crop trims overflow around the center. Patterned banners tolerate stretching; faces practically demand cropping.
- Stretch — pattern art, abstracts
- Crop — anything with a subject
- Platform presets assume cropping
- Passport-style slots prefer strict W×H
Converting cm specs into pixels
Print systems speak centimeters while screens speak pixels; 300 dpi bridges them via px = cm ÷ 2.54 × 300. A common 4×6 cm upload therefore equals 472×709 px — no guessing needed once the formula clicks.
- px = cm ÷ 2.54 × 300dpi
- 3×4 cm = 354×472 px
- 4×6 cm = 472×709 px
- Agency-specified pixels override any formula
Picking output format and quality
Keeping the original type fits most cases. Force JPG for universal photos, PNG where transparency or crisp text matters, WEBP when every kilobyte counts on the web. Quality applies only to lossy encoders; 88 is nearly indistinguishable yet much lighter.
- JPG — default for photography
- PNG — transparency, diagrams
- WEBP — smaller web delivery
- PNG ignores the quality slider
The honest limit of enlarging
Interpolation estimates missing neighbors when growing an image; it cannot restore detail that was never captured. That is why AI upscalers hallucinate texture — useful sometimes, wrong when documents must stay authentic.
- Stay within ~2× zoom
- For big prints, get the original file
- Retina 2x assets need large sources
- Softness signals missing input data
Batch flow and row states
Rows move Ready→Done as they convert. Editing settings flips Done rows to “Needs re-run” so stale outputs never hide silently. Download buttons stay live either way — refreshing is optional, not forced.
- Per-row status chips
- Stale keeps old result until re-run
- ZIP includes completed rows only
- Clear wipes list and outputs together
Quick recipes by task
Government portals: exact W×H + center crop. Social avatars: square preset. Blog bodies: long edge 1200–1600 px. Documents: twice the displayed width in pixels so retina screens stay sharp.
- Portals — Free + Crop
- Avatars/SNS — square preset
- Blogs — long edge 1200–1600
- Docs — display-width ×2
Frequently asked questions
Resizing vs compressing — which one do I need?
Resizing changes pixel dimensions; a compressor keeps dimensions and lowers kilobytes. If a form asks for "400 px max", use this resizer. If it asks for "under 2 MB", use the image compressor. The two tools solve different constraints.
Will my photos get stretched?
Not in ratio modes (% , width, height, long edge) — the other side is computed from the original aspect. Only the Free mode can distort, when you deliberately choose Stretch instead of Crop.
How does crop-to-fill work?
In Free mode, Crop scales the image just enough that both sides cover the target box, then keeps the center. It is what Instagram does to square your photo: subjects stay recognizable while edges get trimmed.
Where do the preset numbers come from?
Social presets are platform-recommended pixels. Print presets are converted from centimeters at 300 dpi: pixels = cm ÷ 2.54 × 300, so 3×4 cm becomes 354×472.
Is upscaling sharp?
Downscaling always looks clean because it discards data. Upscaling must invent pixels through interpolation, so beyond roughly 2× expect softness. For prints larger than your source, re-shoot or obtain the original.
What happens to EXIF metadata?
It is removed. Results are redrawn onto a canvas before saving, so GPS coordinates, timestamps and camera model do not survive. Keep originals if you need that information later.
How does batch processing work?
Files stack up no matter how many times you drop them. Changing settings marks finished rows as “Needs re-run”; pressing Run all converts only pending ones. When everything is done, ALL ZIP packs unique filenames into one archive.
A row failed — what should I check?
Mostly mislabeled extensions, truncated downloads or files over 20 MB per item. Only failing rows are marked, so you can remove them and continue. AVIF requires a modern browser decoder.
References
Checked 2026-08-27. Canvas behavior and format support follow the primary documentation below.