Resize Image to 300KB — Free Online Compressor
Compress any image to 300 KB or less. Works with JPG, PNG, WebP and HEIC — enough headroom that document scans stay readable.
Opens the resizer with a 300 KB target already set
How to Resize an Image to 300KB
Upload your image
Drop it in or select it. A phone photo is typically around 10× over 300 KB, which is a modest reduction — often little more than a quality adjustment.
Tick "Compress to target file size"
The 300 KB target is already filled in when you arrive from this page, so there is nothing to type. The tool then works upward to the best quality that still fits inside 300 KB.
Download your 300 KB image
Click Resize and save the file. It will be at or below 300 KB, and you will get a warning instead of an oversized file if the target is out of reach.
Features
Where Do You Need a 300KB Image?
300 KB is a document-scan budget rather than a photo one. It is generous enough that text in a scan stays legible, which is what most portals at this limit actually care about:
- Document and Certificate Scans — Portals that accept scanned certificates, mark sheets and proofs of address usually allow a few hundred kilobytes, because text needs more resolution than a face does.
- Visa Supporting Documents — Immigration portals often set a per-file limit in this range for supporting documents, separate from the tighter limit on the photograph itself.
- Multi-File Uploads With a Total Cap — When a form limits the combined size of several attachments, bringing each one to around 300 KB keeps the total predictable.
- Property and Legal Portals — Registration and land-record systems accept scanned deeds and agreements at moderate file sizes, since legibility is the requirement.
- Medical Record Uploads — Telemedicine and insurance claim portals accept prescription and report scans in this range, where small print must remain readable.
Portals revise their limits without notice, so confirm the 300 KB figure on the official page for your own form before you submit.
Tips for the Best Quality at 300KB
- For scanned text, keep the dimensions high and let compression do the work — resolution matters more than quality level for legibility.
- JPEG suits photographs and photographed documents; PNG is better for a screenshot or a scan of pure black text on white.
- Scan at 200–300 DPI. Below that, small print stops resolving no matter what file size you allow.
- Straighten and crop the scan before compressing. Skewed borders waste budget and make text harder to read.
- A good starting point for this size is around 1200×1600px.
Frequently Asked Questions
What dimensions should I keep for a document scan at 300KB?
Keep them high — around 1200×1600px for an A4 page. Text legibility depends far more on having enough pixels than on the quality setting, so it is better to hold the resolution and let compression work harder than to shrink the page.
JPEG or PNG for a scanned document?
JPEG for anything photographed or containing images. PNG for a clean scan of black text on white, or a screenshot, where its lossless compression handles flat areas efficiently and avoids the fuzzy halos JPEG puts around sharp edges. Note that PNG ignores a KB target entirely, so if you need a specific file size you must use JPEG or WebP.
My multi-page document is one PDF. Can this help?
This page compresses images. If you have page images and need a single PDF, use the image-to-PDF tool, which combines them and lets you order the pages. To shrink an existing PDF you would need a PDF compressor, which is a different job.
Is 300KB large enough for a photo that needs to be printed?
For a small print, yes. At around 1200×1600px a 300 KB JPEG prints acceptably at postcard size. For anything larger, keep the original — compression artefacts that are invisible on screen become apparent on paper.
Which format gives the smallest file at 300 KB?
JPEG for photographs, though at 300 KB the format question is about page weight rather than legibility — you have room to spare either way. WebP holds about the same quality around 216 KB, so it is the better pick for your own site. For an upload form, stay on JPEG: plenty of portals that accept a 300 KB file still reject the WebP container.
Will the image still look acceptable at 300 KB?
Yes. 300 KB comfortably carries roughly a 1280×1280 pixel photograph, which is past the point where compression is visible at normal viewing size. A typical 3 MB phone photo only has to come down about 10× to fit, and most of that is dimension rather than quality. The tool climbs to the highest quality that still fits 300 KB instead of jumping to a low setting.
Can I upload a HEIC photo from my iPhone and get 300 KB out?
Yes — HEIC, JPG, PNG, WebP, BMP, TIFF, GIF, AVIF and SVG all work as inputs, so an iPhone photo goes straight to a 300 KB JPEG with no separate conversion step. That matters here because an untouched HEIC is usually a few megabytes, roughly 10× over 300 KB. Save as JPEG for the 300 KB target; PDF, PNG, WebP, BMP and TIFF are available too, but PNG cannot be compressed to a size.
Are my images uploaded anywhere?
No. The compression to 300 KB happens in your browser through the Canvas API, so the photo never leaves your device — nothing is sent to a server and nothing is stored. Open your network tab while the 300 KB target is applied and you will see no upload request at all. A 300 KB budget is generous enough to hold roughly a 1280×1280 image at good quality, so there is no reason to trade privacy for it — the whole reduction runs locally, works offline, and nothing about the photo is retained once you close the tab.
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