Image Optimization Checker
Check whether an image is ready to publish. TryImager reads your file locally, scores it out of 100, and shows exactly which characteristic is holding the score down — file size, format, dimensions or compression.
Processed in your browser, not uploaded. Huge photos may fail to decode.
No display width given, so dimension recommendations are estimates based on a typical 1920 px layout.
Your image is checked in your browser on your own device and is never uploaded to a server. Every measurement is computed from a local decode and disappears when the tab is closed or refreshed.
How to check publish-readiness and compare format savings
- Select a supported image in the browse area. The checker reads one file and immediately builds its publish-readiness audit.
- Enter Displayed width in px if you know the website placement. Otherwise select a use case and treat the width advice as an estimate.
- Review the Pass/Review/Warn audit verdict and category breakdown. Click Compare WebP, JPEG & PNG Savings to encode candidate formats in browser memory and see real measured byte differences.
- Use Copy report to keep a text record, or Save next to any candidate format in the comparison table.
- If you want the automatic WebP output with a full before/after visual preview, press Optimize Automatically and download the generated copy.
How to download the result
Checking alone creates no replacement image. Download original retains the source filename and format. In the multi-format comparison table, Save downloads the chosen WebP, JPEG, or PNG candidate directly. After running Optimize Automatically, Download optimized image saves the -optimized.webp file.
File handling and usage data
The checker examines file size and decoded pixels inside your browser. The original and any candidate or optimized copies remain in tab memory until cleared or the page is reloaded; saved downloads remain on your device. Analytics records tool activity and file characteristics such as format or approximate megapixels, but does not receive file contents or names.
Full details are in the Privacy Policy.
Troubleshooting
Why did the audit verdict change after entering a width?
Dimensions are assessed against the display context. A file suitable for a wide banner may be unnecessarily large for a thumbnail, so changing the context can change the verdict without changing any source pixels.
Does a passing verdict mean the file will pass an application form?
No. A form may enforce a format, KB ceiling or exact pixel box unrelated to this web-delivery check. Compare the original measurements with the form's own instructions.
Why does the checker not open my image?
Check that it is a supported image rather than a PDF or HEIC file with a renamed extension. A damaged file or excessive decoded dimensions can also prevent the report; use a smaller valid export.
A quick pass/fail read on any image
Use this checker when you already have an image and simply want to know whether it is fit to publish. It answers one question: is this file the right format, the right size in bytes and the right size in pixels for the way it will be shown?
The output is a score out of 100 plus a per-category breakdown, so a low result always points at a specific cause rather than a vague verdict.
How to read the result
Each category is scored independently, which is what makes the total actionable.
- 90–100: nothing meaningful left to fix. Publish it.
- 75–89: usable, with one clear improvement available — often a format change.
- 55–74: the file is noticeably heavier than it needs to be for its display size.
- Below 55: expect a real load-time cost. Format, dimensions and compression usually all need attention.
Common failures the checker catches
A camera JPEG dropped straight into a page at 4000 px wide. A PNG export used for a photograph because the design tool defaulted to it. A screenshot saved at 3x device pixel ratio. A logo saved as PNG when its transparency could ride along in a much smaller WebP file. All four are invisible in a browser and obvious in the breakdown.
Practical audit examples by placement
Running an audit before uploading assets to a CMS prevents one unoptimized file from dominating page weight. Here is how typical assets behave in the checker:
- Hero banner (1600 px layout width): a 3840×2160 JPEG at 1.8 MB scores poorly on Dimensions and File size; resizing to 2400–3200 px and encoding as WebP typically brings it under 180 KB.
- Article inline screenshot (760 px column width): a 2880×1800 Retina PNG at 950 KB flags both Format and Dimensions; scaling to 1520 px wide WebP keeps UI text crisp at a fraction of the bytes.
- Product card thumbnail (320 px grid card): an 800×800 PNG with an opaque white background flags Format because opaque product shots do not need lossless alpha storage.
Supported inputs and checker boundaries
The checker inspects JPG, PNG, WebP, GIF, BMP, TIFF and SVG files in browser memory up to 16,384 pixels per side (or roughly 260 megapixels total). It evaluates single-file technical readiness — it does not crawl live URLs, inspect HTML srcset markup, or verify portal-specific regulatory rules such as passport head height.
To translate the score's recommendations into a publishing workflow, read preparing images for websites.
Frequently asked questions
What does the checker actually check?
It reads your file's size in bytes, decodes it to get real pixel dimensions, samples the alpha channel for transparency, derives bytes per pixel, and compares all of that with common web delivery practice. Every value shown under Detected information comes from your file; everything under Recommendations is our interpretation of it.
Do I need to know my display width?
No. Without it the checker assumes a typical layout width for the use case you pick and labels the dimension advice as an estimate. Entering the width you actually display makes that part exact.
Does the checker change my file?
Not unless you press Optimize Automatically. Checking is read-only, and nothing is uploaded either way.
Why did an already compressed PNG get a low score?
If the PNG has no transparent pixels and contains photographic detail, the format category penalizes it because lossless PNG stores several times more bytes than WebP or JPEG for the same visual appearance.
How is the estimated optimized size calculated?
Before you run an encode, the checker estimates potential savings from your current bytes-per-pixel density, format and display-width ratio. Pressing Optimize Automatically replaces that forecast with the real byte count of the encoded WebP file.
When not to use this
The score is guidance for web publishing, not a requirement for exam portals or print. A low score does not mean a file will be rejected elsewhere.
It cannot see how your page displays the image, so measure the real display width on your site before acting on dimension advice.