Online Image Optimization Tool
Optimize images for websites without uploading them. Drop in a JPG, PNG or WebP and TryImager analyzes file size in KB, pixel dimensions and compression density locally, scores how well the image is optimized for web delivery (0–100), and re-encodes a smaller WebP inside your browser.
Loading the optimizer…
Your image is analyzed and optimized in your browser on your own device and is never uploaded to a server. The report and any optimized copy stay in this tab's memory until you clear the selection or reload the page.
How to analyze and optimize an image
- Browse for one JPG, PNG, WebP, GIF, BMP, TIFF or SVG image. Analysis starts as soon as the file can be decoded; there is no separate Analyze button.
- Optionally choose where the image will be used and enter its displayed width in pixels. The report updates when those values change.
- Read Detected information and the category breakdown. Estimated optimized size is a forecast, not a promised download size.
- Press Optimize Automatically to generate a WebP copy. Compare the actual bytes, dimensions and previews in Before and after.
- Use Download optimized image only if the result suits your destination. Download original saves the unchanged source; Copy report copies the measurements, not an image.
How to download the result
Download optimized image saves the measured WebP result with -optimized.webp added to the original filename's stem. It appears only after a successful encode. If the save does not start, check your browser's download permissions and Downloads folder, then click again while the result is still open.
File handling and usage data
The selected file and generated WebP are held in this tab as local image data and temporary browser preview URLs, not uploaded for processing. Clear removes the current selection; refreshing loses the in-page result, but does not delete files you have downloaded. Google Analytics can receive format, approximate megapixels, score and savings events, not the photo pixels or filename.
Full details are in the Privacy Policy.
Troubleshooting
Why is my file rejected before the report appears?
HEIC and PDF are not accepted by this optimizer. Use the HEIC converter for a phone photo, or export a PDF page as an image. Corrupt or device-heavy images may also fail to decode; try a smaller, supported source.
Why is the optimized copy larger?
Automatic settings cannot improve every existing encode. Compare the measured bytes rather than the estimate and keep the original if the new copy is heavier or visibly worse.
What if WebP creation fails?
No new result is offered for download. The page keeps the analysis and displays an encoding error. Try a smaller source or a manual converter; a native encoder and its local fallback can both fail on a memory-constrained device.
What image optimization actually means
Image optimization is the process of shipping the smallest file that still looks right at the size it is displayed. Three things drive that number: the format you encode to, the pixel dimensions you ship, and how aggressively the encoder compresses. Getting all three roughly right usually matters far more than fine-tuning any single one.
Large images do not just cost bandwidth. Every byte has to arrive, decode and paint before a page feels finished, which is why oversized images are one of the most common causes of slow page loads on image-heavy sites. Optimized images can help reduce file size and improve web performance.
How the Image Optimization Score works
The same file under the same display-width assumptions produces the same score. This is a weighted heuristic based on locally measured properties, not a visual-quality test, website speed measurement or search-ranking score. When transparency applies, its extra weight is included and all weights are normalized.
- File size (30%): total bytes a visitor must download. Around 150 KB or less is comfortable for a typical web image.
- Format (20%): WebP and SVG score highest, JPEG scores well, PNG scores lower for photographic content without transparency, and legacy formats score lowest.
- Dimensions (20%): your pixel width compared with the display width you enter, or an assumed width for the use case you pick. Roughly twice the display width covers high-density screens.
- Compression (15%): bytes per pixel. Well-compressed web photos usually sit near 0.1–0.3 bytes per pixel.
- Web readiness (15%): whether the format renders natively in browsers, plus penalties for very heavy payloads and very high megapixel counts.
- Transparency (added when alpha is detected): whether the alpha channel is carried in an efficient format.
Formats: JPEG, PNG and WebP
JPEG is lossy and universally supported, which makes it a safe default for photographs — but it cannot store transparency and is usually larger than WebP at similar visual quality.
PNG is lossless. That is exactly what you want for logos, screenshots, and anything with a transparent background, and exactly what you do not want for photographs, where lossless encoding stores detail no one will ever see.
WebP covers both cases: lossy compression for photos and an alpha channel for transparency. Automatic optimization targets WebP, preserving transparency whenever it is detected.
Dimensions and transparency
A 4000 px wide photo displayed in an 800 px column downloads roughly five times the pixels it uses. Telling the optimizer the width you actually display makes its dimension recommendation exact rather than an estimate.
Transparency is detected by sampling the alpha channel of the decoded image, not by trusting the file extension. A PNG saved with a fully opaque background is treated as photographic content; a PNG with real transparency is optimized to WebP with the alpha channel preserved.
How automatic optimization works
Optimize Automatically picks an output format, a quality value and, when useful, smaller dimensions based on the analysis. It then encodes with the browser's native WebP encoder, validates that the result is genuinely a non-empty WebP file, and silently falls back to a libwebp WebAssembly encoder if the native path is missing or produces something unexpected — the behaviour Safari and iOS need.
Every figure in the before/after panel is measured from the encoded file itself: bytes saved, percentage change and the recalculated score. Nothing is predicted after the fact.
If automatic choices do not suit your image, choose the output format and quality yourself with Image Compressor.
Frequently asked questions
Is my image uploaded anywhere?
Image contents and filenames are decoded, analyzed and encoded locally, not uploaded by this tool to a processing service or analytics. Separate Google Analytics and advertising requests can contain usage and request data. Downloading saves a copy on your own device.
What does the Image Optimization Score measure?
It combines five measurable characteristics of your file: total file size, format efficiency, dimensions versus the width you actually display, bytes per pixel, and general web readiness. Images with transparency also get a transparency category. It is a description of the file, not a search ranking score.
Why does the tool usually recommend WebP?
WebP is supported by every current browser, supports transparency, and typically produces a smaller file than JPEG or PNG at comparable visual quality. If your browser cannot encode WebP natively, TryImager falls back to a libwebp WebAssembly encoder that runs locally.
Will optimizing reduce image quality?
Automatic optimization uses a lossy WebP encode at a quality chosen from your image's characteristics, and may reduce dimensions when the image is far larger than its display size. Compare the previews before and after; if you prefer the original, keep it.
Can optimizing make my file bigger?
Occasionally, for images that are already efficiently encoded. When that happens the report says so plainly and you can keep the original.
When not to use this
When a form or client specifies an exact format and size, use the dedicated converter or compressor instead of letting automatic choices decide.
Already well-compressed web images may gain little here, and accepting a format change can break software that only reads the original type.