# Reviewing files one at a time

Review lets you look at each file in a folder inside Trawler and decide whether you want it. You press a key to keep or discard the file on screen, and Trawler shows the next one.

Discarding a file only marks it for removal. Nothing leaves your disk until you run Process marked…, so a wrong key costs you one more key to undo.

Opening Review

  1. On the Files tab, pick a folder in the tree.
  2. Narrow or sort the list if you want to. Review works through the same files, in the same order.
  3. Select a file, then choose Explore → Review in the ribbon.

Review opens over the Files tab. Its Back button appears at the top of the Review panel, and the line describing it replaces the scan summary at the start of the status bar. Review takes the whole width: the folder tree is hidden until you close Review.

Review covers the files in that folder only, not its subfolders, just as the Files tab does. Choose a folder with files before opening Review.

You can also open Review from Largest files or Duplicates. Largest files follows that view's folder scope and filter; Duplicates uses the selected group's files. These Explore views let you show up to four files together.

In Similar, Review stays on the current view and shows one member of the selected group at a time. Use Compare for an A-versus-B comparison instead. Back returns to the view you opened it from. Full screen opens the selected file or the active viewer in full screen.

The screen

The status bar starts with Review, then the folder and how many files are left in the list — for example "Photos · 12 files". Further along, the status bar counts how many of the listed files are marked. In a large folder the list loads more files as you scroll or move past the last one, and the count covers only the files loaded so far.

The list on the left shows each file's name, modified date and size. Its column header does not sort: the files stay in the order Review opened with.

On a row What it means
The tick The file is shown on the right. It is not the tick that marks files for removal.
The circled minus at the end The file is marked to be removed.

Click a file to see it on its own; tick files to compare up to four side by side. Clicking a row anywhere but its tick shows that file alone, even if it was already shown with others. Clicking its tick adds the file to the files shown, or takes it out.

Use the ticks to tell which files are shown. Selecting a row does not mark it for removal. The circled minus remains an indicator; use Keep or Discard to change the mark.

The right side shows the files you picked.

Kind of file What you see
Images The picture, centred. A picture smaller than the space is shown at its real size; a larger one shrinks to fit. A picture you have rotated shows the way you turned it.
Videos The video, with a play bar beneath it: back 5 seconds, play or pause, a position bar and the time. Show audio levels at the end of the bar puts a level meter in the corner of the picture, as in the video compare view
Audio The album art (a music note if there is none), the track's waveform beside its level meter, and the same play bar with Forward five seconds after play. Click the waveform to jump to that point once the track is playing. Drag across the waveform to repeat that passage: the track jumps to its start, and comes back to it at the end, even after you have played another file. Clear loop, the × at the passage's top right corner, stops repeating; so does clicking outside the passage
PDF, Word and PowerPoint, including the older formats (.doc, .dot, .ppt, .pot, .pps), templates and shows (.dotx, .dotm, .potx, .potm, .ppsx, .ppsm), and OpenDocument text and presentations (.odt, .odp) The whole document as pages, one under another, each at its real size and centred, never wider than the space. Pages appear as you scroll to them. The corner shows the page you are on, for example "3 / 12".
Excel workbooks (.xlsx, .xlsm, .xltx, .xltm), older Excel workbooks (.xls, .xlt), OpenDocument spreadsheets (.ods), CSV and tab-separated files (.csv, .tsv) The cells in a grid. A workbook has a tab for each sheet. Click into the grid to move between cells with the arrow keys; click the list and the arrows step through the files again. Original and Text shows the same file as text.
Rich Text (.rtf) The formatted document on a white page, centred and no wider than an A4 page. Scroll it with the mouse wheel. The text can't be selected, so clicking into it never takes the keys away from Review.
Ebooks (.epub, .kepub, .fb2, .fbz, .mobi, .azw, .azw3, .prc, .kfx, .lit) and comics (.cbz) The whole book as one long page, centred and no wider than an A4 page, with its pictures. Scroll it with the mouse wheel. Links to other places show as plain text, and nothing is loaded from the internet.
Emails (.eml, .msg) The subject, then From, To, Cc, Bcc, Sent and Received (each only when the email has it), and the message below. The list beside it shows each attachment's name and size, or No attachments. Attachments can't be opened or saved from here; to get one, open the email in your email app. Pictures carried inside the email are shown. Pictures it would load from the internet are not, so opening an email tells nobody you read it, and its own styling is left out. The list above the message switches between Message, Text (the words alone) and Headers (every line of the email's header). If part of the email can't be read, "Part of this email could not be read." appears above it, and the rest is still shown.
Markdown (.md, .markdown) The formatted document — headings, lists, tables and links laid out — as one long page, the same way an ebook is shown. Pictures it points to, on this PC or online, are not shown.
Web pages (.htm, .html) The page laid out as the website styled it, as one long page. Pictures and styling saved beside it — the folder a browser writes when you save a page — are shown. Nothing on the page runs and nothing is loaded from the internet, so parts that need the website itself, such as search boxes or pictures that were never saved, are missing. To see it as the website intended, close Review, right-click the file in the Files list and choose Open (external).
Plain text, logs, scripts, JSON, XML and similar Read-only text with colours for recognised formats. Large files load as you move through them.
Anything else A hex view showing the bytes and their text equivalents, while Show files with no viewer as hex is on in Settings → General. It is on to start with. With it off, a file that reads as text still opens as text, and any other file shows its icon, its size and "No preview".

Click into the text reader to move the caret with the arrow keys, Page Up, Page Down, Home and End. Hold Shift to select; Ctrl+C copies the selection. Ctrl+Home and Ctrl+End jump to the start and end of the file.

Ctrl+F opens search at the top right. F3 finds the next match; Shift+F3 finds the previous one. Accents count unless you choose Ignore accents. In hex view, enter byte pairs such as EF BB BF. Ctrl+G opens Go to line.

Use View for wrapping, line numbers and column colours. The language picker lets you choose a format when the filename does not identify it. Zoom sits at the bottom right; Ctrl+mouse wheel changes it too. The text and hex fonts are in Settings → General.

If one page of a document can't be drawn, that page says "Couldn't show this page" and the other pages still show.

An older Office file or an OpenDocument file is read without Office. You see its content, but the layout may not match what Office or LibreOffice shows exactly.

When a preview cannot draw something in the file, such as an embedded object, it shows a hatched box in its place and the status bar says how many items could not be shown.

If a whole Word, PowerPoint or Excel file can't be shown, the preview says why: "This file can't be previewed. It may be password-protected or saved in an older format", "This file is too large to preview", "This file couldn't be previewed" or "This file is open in another app". A spreadsheet can also say "This file is no longer at this location" or "Windows didn't allow this file to be read". Move on to another file and Trawler stops preparing the one you left.

Original and Text

Most files can be shown two ways. Original is how the file looks: pages, a grid, a formatted document. Text is the words in it, in the text reader. Press M, or the Text view (M) button, to switch. Press it again to go back. In Review the key acts on the preview you last clicked, the one K and Enter act on.

Kind of file Original Text
PDF, Word, PowerPoint, OpenDocument text, Rich Text The pages The text taken out of the file
Ebooks The book as one page The text taken out of the book
Emails The email None. Use the list above the message for its text and headers
Markdown, web pages The formatted page The file's own source
CSV and tab-separated files The grid (the one you start in) The file as written, a row to a line
Excel workbooks and OpenDocument spreadsheets The grid Every sheet as comma-separated rows, each introduced by its name
Older Word and PowerPoint files and older Excel templates (.doc, .dot, .ppt, .pot, .pps, .xlt) The pages, or the grid None
Text and code files None Always text
Pictures, video, audio The file None

Where a file has only one form the button stays in place and is greyed out. It shows as pressed for a file that is always text, and unpressed for a picture, a video or an audio file.

A workbook's text keeps empty cells, so columns never shift left. Dates and times show as the sheet shows them. A formula shows the value it last calculated. Percentages and currency amounts show as plain numbers, and a date that falls at exactly midnight shows the date alone.

Trawler remembers the form you chose for each kind of file. Open another CSV, in Review or full screen, and it opens in the form you last chose. In full screen the choice holds while you step through the files. A switch you make in full screen does not change a preview already open in Review, but the next one of that kind opens in it. The Organize preview has the same button. The Compare views do not.

If Default display under Settings → General → Text and hex is Hex, the text form of a document shows its bytes.

Buttons

Apart from Back, the buttons show a picture rather than a word. Hover over one to see its name.

Where Button What it does
Ribbon Back Closes Review and goes back to the Files tab
Above each preview Histogram Shows or hides the histogram in the bottom-right corner of a picture. Greyed out for every other kind of file. It is one switch with full screen and the image compare pane — see Images
Above each preview The tick — Keep Clears the mark on that file only and takes it out of the list
Above each preview The circled minus — Discard Marks that file only and takes it out of the list
Above each preview Text view (M) Switches that preview between its original and its text. Greyed out where a file has only one form. See Original and Text
Above each preview Open full screen Opens that file full screen, the same as Enter
Above each preview Open Opens that file in the app Windows uses for it
Explore → Panels Details Shows or hides the Details panel

The buttons above a preview act on that one file. Keep and Discard both take it out of the list, and the next file in the list takes its place. Keep does not stay remembered: the file comes back the next time you open Review on that folder.

Keys

Key What it does
A Keep — clears the mark on the first file shown and takes it out of the list
D Discard — marks the first file shown and takes it out of the list
Space Discards the first file shown if it is unmarked, keeps it if it is marked
K Plays or pauses the audio or video
J / L Moves the audio or video back or forward 5 seconds
Enter Opens the file full screen. A file with no preview opens full screen too, as hex or as the "No preview" page; Open with default app on that page is the only way it opens in another app.
M Switches the focused preview between its original and its text. See Original and Text.
↑ / ↓ Shows the previous or next file on its own
Page Up / Page Down, Home / End Scrolls the first file shown a screenful, or to its start or end, when it is a document, a text file, a book, a Markdown file or a web page. Otherwise they scroll the list.
Esc Closes Review and goes back to the Files tab

After A, D or Space, the file you decided leaves the list. The other files shown move up one place and the next file in the list fills the last place. There is no setting to stop Review moving on.

A discarded file leaves the list, so the list is what you still have to decide. When nothing is left, Review says "Nothing left to review in this folder." If the Files tab has a filter set, it says "Nothing left to review that matches the filter." instead: files the filter hides may still be waiting.

Full screen

Enter, or Open full screen above a preview, opens the file in its own window, filling the screen on a dark background. A video carries on from the point the preview had reached, paused if you had paused it, and if you leave full screen on that same video, the preview picks up from where you left it.

The toolbar runs along the bottom edge, in a row of its own under the file. It never covers the file, and for a video it never covers the video's own play controls. It is pinned to start with, so it is always there. Press Pin toolbar to unpin it. An unpinned toolbar slides away 3 seconds after the mouse leaves it, the file grows to fill the space, and moving the mouse to the bottom edge of the screen brings it back. Trawler remembers whether you pinned it, for pictures, videos and every other file alike.

Over a picture or a video with the toolbar unpinned, the mouse pointer hides after 3 seconds without movement. Move the mouse and it comes back. With the toolbar pinned the pointer stays.

The toolbar always has the same buttons in the same places, whatever the file. A button that does not apply to this file is greyed out rather than hidden. From left to right: Pin toolbar; Text view, Keep, Discard, Rotate 90°, Audio levels, Histogram and Auto-advance; Previous, the file's name, its place in the list ("3 of 12") and Next; the zoom buttons; and Close, always last. Audio levels shows or hides the level meter in the corner of a video. Histogram does the same for a picture, showing its histogram in the bottom-right corner. Images explains how to read it.

When the window is too narrow for everything, a … button appears before Close. The file's name, its place and Previous and Next move into its menu first, then the zoom buttons. Pin toolbar, the left-hand buttons and Close stay on the bar.

Button Key What it does
Pin toolbar Keeps the toolbar on screen until you press it again
Text view M Switches between the file and its text. See Original and Text
Keep A Clears the mark on this file and takes it out of Review's list
Discard D Marks this file and takes it out of Review's list
Rotate 90° R Turns a picture a quarter turn. Trawler remembers it, here and on the Similar tabs.
Auto-advance V When on, Keep and Discard move on to the next file. On to start with.
Previous / Next ← / → Shows the previous or next file in Review's list
Zoom out / Zoom in - / + Zooms the file. The size is shown between the two buttons.
Fit F Goes back to the starting size
Close Esc Goes back to Review

Zoom goes in the steps that suit the file. Documents and books go from 50% to 400% in steps of 25%; Rich Text starts at 100%. Text, hex and spreadsheets go from 10% to 400% in steps of 10. A video has no zoom, so the zoom buttons are greyed out.

Space discards an unmarked file and keeps a marked one. K plays or pauses audio and video, and J and L move them back or forward 5 seconds. Turn the mouse wheel over a picture to zoom it, and drag a zoomed picture to move it. In a PDF, Word, PowerPoint or Rich Text document the wheel scrolls; hold Ctrl to zoom one step at a time. Books, Markdown files and web pages zoom with + and - only.

In a document, a text file, a book, a Markdown file or a web page, the keys scroll it as they do when you compare documents. ↑ and ↓ scroll a line, Page Up and Page Down scroll a screenful, and Home and End go to the start and the end. ← and → still show the previous or next file. Over a picture, a video or an audio file, ↑ and ↓ show the previous or next file, the same as ← and →.

A spreadsheet opens full screen ready for the keys: the arrow keys move between its cells, so use Previous and Next on the toolbar to change file. The toolbar's zoom buttons zoom the grid; it has no zoom slider of its own here.

A file with no preview opens full screen too, as hex, or as a page with its icon, size and "No preview" if you turned off Show files with no viewer as hex. Open with default app on that page opens the file in the app Windows uses for it, and only when you press it.

Right-click the file, in a preview or in the full-screen window, for Explore here, Copy path and Open (external). This is the way to open the file in the app Windows uses for it without leaving Review. In a preview, Shift+F10 or the Menu key opens the same menu. This menu also replaces the browser's own menu over a book, a Markdown file or a web page.

From the full-screen window, Explore here and Open (external) close full screen first, so the folder or the other app is not left behind a dark screen.

When you close the window, Review's list shows what you decided there.

Show on the other display

With a second monitor connected, Show on the other display fills that monitor with one file while you carry on working on this one. The button sits beside Details in Review, beside Full screen in each compare view, in the header of Organize's preview, and at the bottom of the Files screen. With one monitor it is greyed out and says "Needs a second display".

The other monitor shows the file and nothing else: no buttons, no ticks, no Keep or Discard. You still decide on this screen. It follows what you are looking at:

  • In Review, the first file shown.
  • In a compare view, the side you last clicked, A or B. It stays on that side as you move through the groups.
  • In Organize, the previewed file.
  • On the Files screen, the selected file.

A video there plays on its own and is not kept in step with the one on this screen. A song shows its cover picture, or a plain music note when it has none.

To close it, choose the button again, press Esc on that monitor, or move the pointer there and choose the × that appears in the corner. It also closes when you leave the screen that opened it. Opening it from another screen moves it to that screen's file.

Comparing files side by side

Tick more rows to see the files next to each other. Each file you add goes after the ones already shown. Clicking a row itself, rather than its tick, goes back to that one file.

Up to 4 files show at once: two side by side, three in columns, four in a grid. Add a fifth and the file you added first leaves the preview, so the four you added last are shown.

With several files shown, A, D and Space act on the first file shown only. It leaves the list, the others move up, and the next file fills the last place. ↑ or ↓ goes back to one file.

K and Enter act on the first preview, unless you are working a video's own controls in another one.

Seeing the files' properties

The Details panel sits beside the previews while Review is open: one column per file shown, in the order shown, with rows for size, dates and whatever else the files carry — camera, length, author. Rows where the files differ are in bold. Show or hide it with the Explore → Details command in the ribbon. Trawler reads the files only while the panel is open. With one file shown the panel still lists that file's properties.

Changing the filter while Review is open

The filter narrows the Review list; it does not close Review. Type in the filter box or pick a kind of file, and the list starts again with the files that match, showing the first one. Files you have already discarded stay out of the list even when the new filter matches them. A file you unmark somewhere else, such as the Duplicates tab, can come back the next time the list loads.

A change that ends where it started, before the list updates, changes nothing.

When the list is empty under a filter, either because nothing matched or because you have decided every file that did, Review says "Nothing left to review that matches the filter." Change or clear the filter to see the rest of the folder.

When Review closes by itself

Review works through the folder and sort it was opened on. If either of them changes, Review closes and you are back on the Files tab.

When a file can't be shown

The message appears in that file's preview. Keep and Discard stay available, and so does Open unless the file has gone.

Message What it means
"This file is no longer at this location" It was moved or deleted after the scan. Open is greyed out. Marking it is harmless.
"Windows didn't allow this file to be read" You don't have permission to read it.
"This file is open in another app" Close it there, then show it again.
"This book is protected, so it can't be shown" The ebook has copy protection. Open it in the app you bought it with.
"This book is too large to show" Ebooks over 100 MiB are not shown. Try Open.
"This email is too large to show" Emails over 64 MiB, attachments included, are not shown. Try Open.
"This file couldn't be shown" or "This file couldn't be read" The file is damaged, or Windows can't draw this format. Try Open.

Some problems are reported in the status bar instead:

Message What it means
"The file list couldn't be loaded" The list failed to load. Close Review and open it again.
"Couldn't change the marks." A keep or discard did not go through. Try it again.
"Two preview types claim the same file type — see the log." A fault in Trawler, not in your files. Review can't open until it is fixed.

After you've decided

Discarded files leave the list but stay marked. They show again, with the circled minus, the next time you open Review on that folder, so you can still change your mind. When you are done, press Back or Esc and run Process marked… to choose what happens to them. See Processing.

The circled tick means Keep. The solid circle with a minus means Discard. These are your review choices; files are only removed when you process your marked files.