Compress image files to a target size without visible loss
A job portal rejects your 4 MB photo, your website loads slowly, or your email bounces because of attachments. Your todo.is agent shrinks each image to the file size you need: it picks the best format, lowers dimensions only if needed, tunes compression and checks that the picture still looks right.
The prompt
- Compress the attached images: [ATTACH THE IMAGES]. Each must be under [MAX FILE SIZE]. They will be used for [USE]. Keep the dimensions at least [MIN DIMENSIONS] if possible. Choose the best format for each one, remove hidden metadata, and compare each result with the original so there are no visible blocks or color banding. Send me the files in a ZIP with a list of before and after sizes.
What to change
- [ATTACH THE IMAGES]: Attach the images (JPG, PNG, WebP, HEIC, up to 50 MB each). Send them as files so the chat app doesn't shrink them first.
- [MAX FILE SIZE]: E.g. "100 KB", "500 KB", "1 MB" or "as small as possible without visible loss".
- [USE]: E.g. "a website" (fast loading), "an online application form", "email" or "printing".
- [MIN DIMENSIONS]: E.g. "1600 px wide", "600 x 600 px" or "don't care".
Example result
- Compression report: 12 website images
- Target: under 300 KB each · min 1600 px wide · use: website
- Before and after
- • hero_beach.png · 8.9 MB → 286 KB · saved as WebP, 1920 px wide
- • team_photo.jpg · 4.2 MB → 241 KB · JPG quality 80, 1600 px wide
- • logo_full.png · 640 KB → 38 KB · kept PNG (sharp edges, transparency), palette reduced
- • menu_screenshot.png · 2.1 MB → 172 KB · kept PNG for crisp text
- • ... 8 more in Compression_list.csv
- • Total: 38.4 MB → 2.6 MB (93% smaller)
- What your agent did
- • Photos: saved as WebP or JPG at quality 75 to 82. The eye rarely sees a difference above 75
- • Graphics, logos and screenshots: kept as PNG, reduced colors and optimized; JPG would blur text
- • Large photos: reduced from 6000 px to 1920 or 1600 px wide. A website never shows more than that
- • Metadata removed: camera data and GPS location, which also protects your privacy
- • Checked: zoomed into skies, faces and gradients for blocky areas or banding. Two images needed a slightly higher quality setting to look clean
- Which format to use
- • JPG: photos, good everywhere
- • WebP: photos and graphics on websites, usually 25 to 35% smaller than JPG
- • PNG: logos, icons, screenshots and anything with transparency or text
- • HEIC (iPhone): small, but many websites and forms don't accept it. Convert to JPG first
- If an image still won't fit
- • Lower the dimensions a bit more, or crop out empty areas
How to do it with todo.is
- Copy the prompt and set the maximum file size.
- Paste it into todo.is on the Today screen with the images attached, or send them to your agent on WhatsApp, Telegram or email.
- Your agent compresses each image to the limit and checks it visually.
- Download the ZIP, or reply "keep the hero image sharper" to adjust one.
Tips for a better result
- For websites, WebP at about quality 80 is usually the best trade between size and looks.
- Most of the weight is pixels. A 6000 px photo shown 1200 px wide on a page is wasting about 25 times the space.
- Don't compress logos and screenshots as JPG. PNG keeps text and edges sharp at a small size.
- Keep your originals. Compressing an already compressed JPG again loses a little more quality every time.
compress image: FAQ
- How do I compress an image to 100 KB? Give "under 100 KB" as the limit. Your agent reduces dimensions and tunes compression until the file fits, then checks it still looks good.
- Does compressing an image reduce quality? A little, but done carefully you won't see it at normal size. Your agent compares each result with the original.
- What is the best format for small image files? WebP is usually smallest for the web. JPG works everywhere for photos, and PNG is best for logos and text.
- Can I compress many images at once? Yes. Attach them all or a ZIP, and your agent compresses each one to the same limit.
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