Choose image compression settings by checking the saved file
Choose image compression settings by checking the saved file
By Hello Keyboard (AI-assisted)
Before compressing an image, decide what must remain usable: a photograph's texture, the small text in a screenshot, or a transparent edge. The export needs to fit its destination while preserving those details. A smaller file alone does not settle the choice.
Keep an original and write down the requirements
Save an untouched master. For each trial, start from that master rather than recompressing the previous output. Repeated lossy encoding can introduce additional damage, and it makes comparisons harder to interpret.
Check the receiving website or application for accepted formats, a file-size limit and any required pixel dimensions. These are separate requirements. An image can fit a byte limit while having the wrong width or height.
For practice, choose a non-sensitive image you have permission to use. Note its format, dimensions and file size before changing anything.
Choose a format that the destination accepts
For a photograph without transparency, JPEG and WebP are useful candidates when the destination supports them. Compare actual exports rather than assuming one format will always be smaller.
JPEG cannot retain transparency. If transparent areas matter, do not select JPEG unless you deliberately prepare an opaque version with the intended background. When trying WebP, check the downloaded file against the background where it will appear.
Screenshots, diagrams and logos need particular attention around lettering and sharp edges. Keep the original PNG as a candidate if the destination accepts it and conversion makes those details worse. Renaming a file's extension does not convert its contents.
Make one controlled export
The Hello Keyboard Image Compressor provides a simple place to try this workflow. Its instructions list JPEG, PNG and WebP inputs up to 20 MB, with JPEG or WebP output. They describe browser processing without an account, a quality control, a preview and a resulting file size.
Choose your practice image, select an accepted output format, start at quality 80 and select Compress image. Inspect the preview, then download the result with a name that records its format and quality setting.
The page says it preserves the original dimensions. If the destination requires a smaller width or height, prepare an appropriately resized copy in an image editor first. Lowering this compressor's quality setting will not satisfy a dimension requirement.
Compare quality without changing the source
Make another export from the same source and in the same format, this time at quality 70. These settings are trial points, not recommended values for every image. A quality value of 80 does not mean that the file will be 80% of its former size or retain a measured 80% of its detail.
Open both saved files alongside the original. Inspect them at the intended display size, then at 100% zoom to examine small details. Compare the same regions:
Letter edges and punctuation in screenshots.
Fine texture such as hair, fabric or foliage in photographs.
Smooth areas where banding or blotches would be distracting.
Transparent boundaries against the intended background.
If an important detail deteriorates, try a higher setting or retain the original. Avoid choosing from thumbnails alone.
Check bytes before deciding
Record the downloaded file's byte count, not just a rounded size label or its allocated “size on disk.” Compare like units and check the destination's limit.
For illustration only, suppose a source is 900,000 bytes and two trial exports are 420,000 and 280,000 bytes. These are invented figures, not measurements from the tool. If the smaller export blurs essential lettering but the larger one remains readable, the 420,000-byte version may be the useful choice. It still saves 480,000 bytes compared with that illustrative source.
The tool's documentation warns that an already optimized image can become larger after conversion. Keep the original when a new export provides no useful improvement.
Before using the chosen file, reopen it in the receiving application and confirm its format, dimensions and appearance. Keep a short record of the source, settings and chosen output so the decision can be repeated.
Disclosure: This tutorial was prepared by an AI assistant on behalf of the Hello Keyboard operator. Tool details come from its instructions read on 8 November 2026. No interactive compression test, benchmark or independent privacy audit was performed for this article.