Preview canvas objects

Object Preview lets you inspect a canvas object in a focused viewer while keeping the canvas nearby. Use it for material that needs more room than the object itself: images, PDFs, video, audio, text files, CSV files, Office or HWP documents, website links, embedded media, and generated output.

Preview is not the same as download. Preview is for review in context. Download is for taking the source file outside ALLO. Open link is for leaving ALLO and using the original website or external service.

Availability and permissions

Open Object Preview

Select a supported object and choose Preview from the Element menu, inline toolbar, double-click behavior, or other visible preview entry when available. The exact entry point depends on object type, permission, upload state, and device.

If Preview is missing, the object may still be valid. It may be a type that does not support in-canvas preview, a pending upload, a generated result that has not finished, a file blocked by retention or storage policy, or an object you can see but cannot inspect in detail.

When a file was just uploaded, wait before reopening the menu. Preview depends on processing, thumbnails, internal conversion, and safe URL checks that may finish after the object first appears.

Move, resize, maximize, and close

On desktop, Object Preview behaves like a floating window. You can drag it by the header, resize it from edges or corners, bring it to the front, maximize it, restore it, and close it without losing the canvas behind it. The window remembers its last desktop position, size, and maximize state.

Use this when reviewing a file against nearby notes. For example, keep a PDF open while checking comments, keep a video open while reading timing notes, or compare an image against labels on the canvas.

The desktop preview does not use a heavy backdrop. Background canvas interactions can remain available, but be intentional: if you click the canvas behind the preview, you may change selection or focus.

On mobile, the preview is full-screen or uses a platform-specific path. There is no desktop-style floating window because the screen is too small to make dragging and resizing useful.

Preview images

Image preview is built for pixel inspection. It can show a larger version of the selected image, provide zoom and pan behavior, navigate through nearby images, rotate or flip in the viewer when available, and download when allowed.

Generated-image prompts and internal provenance are not shown as extra footer panels in the image preview. The user-facing job is inspection: look at the pixels, compare nearby images, and save the image if allowed.

If an image still loads high-resolution data, the preview may show an intermediate source first. Wait for the full image before deciding that the image is blurry.

For crop, replace, remove background, restore image, and image review workflows, see Work with image objects.

Preview PDFs and Office or HWP documents

PDF preview opens a document viewer with page rendering, page navigation, thumbnail sidebar behavior when available, zoom controls, fit-to-screen, reset zoom, text selection, and clickable PDF link areas when the document supports them.

Office and HWP documents can route through ALLO's internal PDF preview path when the source is an internal uploaded file. That keeps private files inside ALLO's own preview and download flow instead of sending the original document to an external viewer. If your goal is to turn a document into a review canvas, use Import PDF and Office files instead.

PDF and Office/HWP-to-PDF preview has a confirmed 100 MB preview limit. When the file is over the limit, use Download if downloads are allowed. If the source size is unknown, ALLO still enforces a downloaded-byte ceiling while loading so an oversized document does not overwhelm the browser.

If the PDF viewer shows a loading stage, it may be fetching the file, warming the Office/HWP conversion cache, loading the PDF runtime, or rendering pages. Wait for the first page before retrying.

Preview video and audio

Video preview opens a player with visible playback controls. Audio preview opens an audio player and can show waveform-style playback when waveform data exists. Generated audio may include transcript text or a saved playback speed when the result carries that data.

Starting one audio preview can pause other non-sound-effect audio in the canvas. This prevents multiple recordings, generated audio, or audio previews from playing over each other.

If the browser blocks autoplay with sound, use the visible Play control. If a media file fails but Download is available, download can help confirm whether the source file itself still works.

Preview text, Markdown, HTML, JSON, and CSV

Text-like files can open in a readable preview. Markdown files can show a rendered preview with a source-code fallback. HTML files open in a sandboxed preview with desktop, mobile, and source-code modes when supported. JSON files can be pretty-printed for easier reading.

Text and CSV preview have a 50 MB guardrail. Large text or CSV files can make a browser preview unusable, so ALLO limits in-browser preview size and may show a fallback or error instead.

CSV preview opens a scrollable table. Wide files should scroll horizontally rather than squeezing each column until the data becomes unreadable. If the CSV is too large or needs real spreadsheet analysis, download it or use the source spreadsheet app.

HTML preview is sandboxed. Uploaded HTML must not become part of the ALLO app origin or read ALLO cookies, local storage, or other private app data. Links inside HTML previews may open outside the preview when they leave the safe internal page.

Preview links, websites, YouTube, and embeds

Website links often open as a rich card with a thumbnail, title, and Open link action. Supported multimedia embeds, such as YouTube, can render through an iframe path when the source allows it. Some copied iframe snippets can render inline when ALLO recognizes and safely sanitizes the iframe source.

Not every website can be embedded. Many websites block iframe rendering, require sign-in, or need browser features that do not work inside a sandbox. In those cases, Object Preview should show an open-link fallback rather than a blank unsafe page.

Use Open link when you need the original site. The external site controls its own login, permissions, cookies, paywalls, and playback restrictions. ALLO canvas access does not grant access to that external service.

For adding and reviewing external references, see Use links and YouTube embeds.

Preview generated output

AI Studio and other generation flows can create canvas objects that appear as pending placeholders first. During generation or file processing, preview, download, edit, replace, and object-specific actions can be disabled.

Wait for the placeholder to finish before treating missing preview as an error. If the result is a webpage-style preview, inspect links, layout, claims, and visible text before sharing it with teammates. If the output is wrong, revise or regenerate it before using it as a reviewed artifact.

If a generated output stays pending, refresh the canvas and check whether the placeholder still exists before submitting the same request again. See Review AI output and share web pages for generated result review.

Preview versus Download versus Open link

Use Preview to inspect content without losing canvas context. Use Download to save a file to your device. Use Open link to leave ALLO and open the original external page.

These controls can appear independently. A PDF may preview and download. A shared file may preview while download is blocked. A website may have Open link but no download action. A YouTube embed may preview inline when supported and still offer Open link for the original YouTube page.

When a client or guest says they can see a file but cannot download it, check sharing restrictions before assuming a file failure. Preview permission and download permission are intentionally separate in some shared workflows.

Collaborate while previewing

Object Preview helps people inspect material without breaking the canvas conversation. Keep the preview open while reading surrounding notes, then add comments to the object or nearby canvas area. If feedback belongs to the file, image, video, or link itself, use an object comment. If feedback belongs to the whole page, use a page comment. See Comments and mentions for the full review flow.

For reviews, ask people to use direct object links when they need someone to inspect a specific item. Use Copy link from the object menu when available. For sharing broader access, use Share a canvas.

If the preview contains sensitive material, check canvas access before inviting external people. Anyone with access to the object may be able to inspect it according to their role and workspace policy.

What can go wrong

If Preview is missing, check object type, upload state, generation state, permissions, and workspace restrictions.

If preview opens but content fails, refresh the canvas, wait for processing, then try again. If Download is available, download can confirm whether the source file still exists.

If a PDF or Office/HWP document is over 100 MB, use Download when allowed. The preview limit protects the browser and canvas session.

If text or CSV preview is too large, download the file or use a dedicated app. The preview surface is for inspection, not heavy data work.

If an embedded website fails, use Open link. Many sites block embedding on purpose.

If the wrong object opens, close preview, select the object again, and open the element menu from the object boundary. Dense canvases make nearby-object selection mistakes common.