Compress image to 400KB for email attachments
400KB is a generous budget — enough that a full photograph survives close to intact. The tool re-encodes on a canvas and only trims quality as far as it needs to, typically holding around 1200x900 pixels. Use it when a site enforces a limit rather than when you need the smallest possible file. Nothing is uploaded.
A browser-based compressor that re-encodes an image until it falls under 400KB, a budget that holds roughly 1200x900 pixels of photographic detail.
Related terms
With about 1200x900 pixels of budget the encoder works at a quality level where differences are invisible outside a pixel-level comparison.
At 400KB you rarely need to lose resolution. Resize only if the destination also caps the dimensions.
Canvas re-encoding does not carry EXIF across, so camera and location data generally do not survive the process.
Compression runs on your own device using the Canvas API. There is no upload step and no server involved.
Compress Image to 400KB is a permissive limit. Most photographs reach it with quality reduction alone, holding around 1200x900 pixels, so the tool is usually satisfying a rule rather than rescuing a file.
The image is decoded, drawn to an offscreen canvas and re-encoded. Quality is stepped down and measured against the 400KB ceiling on each pass; dimensions are only reduced if quality reduction alone cannot reach the target, which is uncommon at this size.
Content management systems, marketplace listings and forums that enforce a 400KB ceiling for page-weight reasons rather than storage.
Reaching 400KB means discarding roughly 10x the data in a typical 4MB phone photograph, and nothing restores it. Repeated compression still accumulates damage, so work from the original rather than a file that has already been through this once.
The image is decoded and re-encoded by your own browser using the Canvas API. There is no upload endpoint, so the file cannot reach a server; closing the tab discards everything.
