Hide secret text inside a PNG image
LSB steganography in the red channel — visually indistinguishable, recoverable with the matching decoder. Runs locally.
image/* · runs locally · nothing uploaded
How it works
Pick an image, tune the options, then download the result. Everything runs in your browser.
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Pick a carrier image
Any image works as input — it becomes a PNG after encoding.
Files stay in memory as an
HTMLImageElement— the original bytes are never uploaded, and EXIF metadata is preserved until you explicitly transform it.inputuploadcanvaslocaldecodeinput · bytesimage · loadedload: image/*
loaded · decodedcanvas · ready - 02
Type your message
UTF-8 text. The bar at the bottom shows how much of the image's capacity is used.
Encoder quality is exposed where the format supports it — JPEG and WebP get a
0–1quality slider; PNG is lossless. Options re-render the canvas immediately.textoptionslive previewencoderqualitylen · tunable0 chars · liveutf8.encode(text)
options applied · liveencoder · live - 03
Write LSB bits
The length (32 bits) and payload are written to the red channel's LSB, pixel by pixel.
Pixel work runs on the Canvas 2D context —
drawImageresamples with the browser’s bilinear filter andgetImageData/putImageDataback per-pixel passes.lsbrenderCanvas 2Dpreviewpx-perfectbits · resampled0 · px-perfectR = R & ~1 | bit
preview · livepx-perfect - 04
Download PNG
Save as PNG — JPEG would destroy the hidden bits.
Downloads ship via a hidden anchor with an object URL — no server round-trip, and the file on disk is untouched. The output filename inherits a sensible suffix.
exportdownloadblobclient-sideobject URLok · blobready · savedstego.png
shipped · ready to shipsuccess
Browser-only image work that scales
Convert with quality control
JPEG/WebP let you pick a 0–1 quality. Default 0.92 is a good compromise of size and visible quality.
PNG isn’t free
Use PNG only for transparency or sharp edges. For photos, WebP is smaller at the same perceived quality.
Strip EXIF for privacy
Photo EXIF often contains GPS, camera model, and timestamps. Strip before sharing public uploads.
Watch the colour profile
Convert to sRGB before web export. Wide-gamut images render oversaturated in non-managed browsers.
AVIF when it’s available
AVIF beats WebP on size at the same quality. Detect support via <picture> with fallbacks.
Lazy-load below the fold
Add loading="lazy" on <img>. The browser handles scheduling — no IntersectionObserver needed.
When to use this tool
Common workflows it speeds up.
CTF challenges
Build your own LSB-stego puzzles. Decoded into a Canvas 2D context — original bytes never leave the tab, so you can process customer-uploaded photos, internal screenshots, or sensitive diagrams without privacy concerns.
px-perfectHidden watermarks
Embed authorship strings invisibly. Encoders expose quality 0–1 where the format supports it (JPEG, WebP); PNG and AVIF stay perceptually lossless. Pick 0.85 for web, 0.95 for archival, 0.7 for thumbnails.
quality-tunableEaster eggs
Drop secret messages into shareable images. Pair with the EXIF Stripper before sharing user-uploaded photos publicly. Camera serial numbers, GPS coordinates, and timestamps often hide in image metadata and leak more than the picture itself.
format-awareImage checksums
Carry hashes in the file without metadata. Output preserves colour profile (sRGB) so it renders consistently across browsers, monitors, and print pipelines. Wide-gamut workflows can opt into Display P3 for modern Apple devices.
EXIF-safeTeaching
Demonstrate steganography in security classes. Re-runs only on option changes, never on window resize, so the canvas stays responsive on large images. drawImage uses the browser's bilinear filter for fast resampling.
client-sideCasual notes
Send a secret tagline tucked into a photo. Downloads as .png, .jpg, .webp, or .avif with the correct MIME so editors apply native handling on save. The filename inherits a sensible suffix derived from the input.
compression-readyFrequently asked questions
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