Compress any image to 300 KB online for free. Perfect for high-quality blog images, newsletter headers, and editorial photography. No watermarks, no sign-up required.
Perfect for high-quality blog hero images, email newsletter headers, editorial photography on magazine-style websites, and any image where visual fidelity matters but you need to stay under a third of a megabyte.
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To compress an image to 300 KB (307,200 bytes) for free, drop it into SammaPix Compress and adjust the quality slider until the output meets the target — for most photos, quality 55-75% reaches 300 KB. Processing happens 100% in your browser using the Canvas API — no upload, no signup, no watermark. Tested on 100 real images: SammaPix matched SSIMULACRA 2 quality scores above 65 (no visible loss) at all output sizes >= 50 KB. For sizes below 25 KB, expect visible compression artifacts on photographic content — vector-style images and screenshots fare best.
Open the SammaPix Compress tool and drag your image into the drop zone. Supports JPEG, PNG, WebP, and GIF.
Adjust the quality slider until the output size is at or below 300 KB. Lower quality = smaller file.
Download your compressed image instantly. Everything runs in your browser — your photos never leave your device.
Typical results when compressing a photo to 300 KB.
| Property | Original | Compressed |
|---|---|---|
| File size | 4.4 MB | 300 KB |
| Quality | 100% | 80-90% |
| Size reduction | — | ~93% |
| Format | JPEG / PNG | JPEG / WebP |
At 300 KB you can maintain 1400-1800 px wide images at quality 82-88% — the sweet spot for blog headers that look stunning on retina displays.
Newsletter email clients like Gmail clip messages over 102 KB of HTML — keep each newsletter image at or below 300 KB to avoid triggering the clip threshold when combined with your email markup.
For editorial photography, use WebP at 300 KB to preserve color gradients and skin tones that JPEG sometimes banding at lower file sizes.
Pair 300 KB hero images with srcset to serve smaller versions on mobile — a 300 KB desktop hero can be a 100 KB mobile version at 800 px wide.
Ready to compress?
Use Compress to reduce your images to 300 KB or below, or Convert to WebP for even smaller files at the same quality.
Yes — a 1400×800 px image at 300 KB in WebP or JPEG looks near-lossless on screens. Most professional blogs use hero images in the 200-400 KB range. At 300 KB, the image loads in under 150 ms on a typical broadband connection.
Design your header at 600×300 px (standard email width), export at quality 85%, and compress with SammaPix. At these dimensions, 300 KB is generous — you will likely end up around 150-250 KB with excellent quality. This leaves headroom for the email HTML itself.
Choose 300 KB when the image has fine details that matter — editorial portraits, food photography, product close-ups. For generic blog thumbnails or social media cards, 200 KB is sufficient and loads slightly faster.
For landscape images: 1400-1800 px wide at quality 82-88%. For square images: 1200-1400 px. For portrait images: 1000-1200 px wide. These ranges produce files that hover around 300 KB with sharp, detailed results.
Compress to 200 KB
Ideal for blog images, social media posts, and product photos where you need a good balance between quality and file size.
Compress to 500 KB
Perfect for high-quality blog images, portfolio sites, presentations, and any context where visual detail matters.
Compress to 1 MB
Ideal for print-ready web images, high-resolution product photos, and professional portfolios where maximum detail is needed.
100% private
All compression happens in your browser. Your images never leave your device — nothing is uploaded to any server.
Instant results
No waiting for server processing. Compress images in milliseconds using your device's own hardware.
Free, no limits
Compress as many images as you want. No watermarks, no sign-up, no daily caps on the free plan.