The direct answer: what your comp titles should do
Your comp titles should place your book on a shelf in one sentence. Name two published books your readers already know, use the first as the familiar anchor and the second as the twist that shows what changes, and state your genre, tone, and reader beside them. A dark thriller for adult thriller readers might be framed as one familiar anchor meets one distinct twist, followed by a single sentence about what your plot does differently. That pairing is the whole job: orient fast, promise something specific, then stop and let your own story take over.
What a comp title actually is
A comp title is a published book you mention so a stranger can locate your book without reading it. Agents, editors, booksellers, and readers all carry a mental map of shelves, and a comp points at a spot on that map. The anchor comp says which neighborhood your book lives in. The twist comp says which street it turns down. Neither comp claims your book equals those books. Both comps together narrow the guess about what kind of reading experience you deliver.
The tool on this page does not look up sales figures, rankings, or market data of any kind. It takes the titles you type, the genre you pick, the tone you pick, and the audience you describe, and it assembles those entries into framing lines with fixed rules. Every result on this page comes from your own words run through deterministic checks. Nothing is fetched from a database, nothing is scored against outside bestseller lists, and nothing leaves your browser.
Why two comps beat one
One comp gives the reader a single point, and a single point cannot show direction. If you name only one familiar thriller, the listener knows the broad area but cannot tell whether your book leans darker, funnier, more romantic, or more procedural than that anchor. A second comp supplies the direction. The gap between the two titles is where your book sits.
Two comps also protect you from overclaiming. A single giant anchor invites the response that your debut is nothing like that phenomenon. When that giant sits beside a smaller, closer twist, the pairing reads as positioning rather than boasting. The anchor orients, the twist qualifies, and the combination sounds like a working writer who knows the shelf.
Three or more comps usually weaken the line. Each extra title divides attention and adds another comparison you must then justify. Queries, pitches, and cover meetings move fast, and two well-chosen titles survive that speed. Keep the pair tight and spend the saved words on your own plot.
How the tool math works
The tool runs five fixed checks and reports how many pass. Each check is worth one point, and the total is shown as a framing score out of five. The five checks are: a first comp is entered, a second comp is entered, the two comps differ from each other, the audience description holds at least two words, and the genre-plus-tone slot is set, which always passes because the form always carries a genre and a tone selection.
Work through a concrete case. You pick thriller as the genre and dark as the tone. You type adult thriller readers as the audience. You enter The Night Shift as the first comp and Harbor Light as the second comp. The tool counts comps entered as 2 of 2. It compares the two titles in lowercase and finds they differ, so the distinctness check passes. It splits the audience on whitespace and counts 3 words, so the specificity check passes. The genre-plus-tone check passes automatically. The framing score is 5 of 5, and the verdict passes with a pairing line built from your entries.
Change one input and watch the arithmetic move. Delete the second comp so only The Night Shift remains. Comps entered drops to 1 of 2. The distinctness check fails because there is nothing to compare. The audience still holds 3 words, and genre-plus-tone still passes. The score becomes 3 of 5: one point for the first comp, zero for the second, zero for distinctness, one for the audience, one for genre-plus-tone. The verdict warns that the twist slot is empty and tells you which slot to fill.
Try a different failure shape. Enter The Night Shift in both slots, with the second typed in different capitalization. The lowercase comparison catches the match, so distinctness fails even though both slots are filled. Comps entered reads 2 of 2, but the framing score is 4 of 5, and the verdict warns that the pair must differ. The fix the tool recommends is concrete: keep one copy as the anchor and replace the other with a title whose plot engine or relationship stakes differ.
Try a thin audience next. Keep both comps distinct but shorten the audience to readers. The whitespace split counts 1 word, so the specificity check fails. The score lands at 4 of 5 and the verdict warns that one word cannot place the book. Lengthen the audience to adult thriller readers and the check passes again at 3 words. That is the entire calculation: count entries, compare the pair, count audience words, add the genre-plus-tone point, and report the total.
Reading your result blocks
The verdict block is the headline judgment. It states how many comps you entered, how many of the five checks passed, and what to do next in one or two sentences. A passing verdict hands you the pairing line and tells you where to use it. A warning verdict names the exact slot that fails. An info verdict appears when both title slots are empty and explains how to pick an anchor and a twist from scratch.
The metrics block holds four figures. Comps entered shows 0 of 2, 1 of 2, or 2 of 2 with a hint naming your entries or naming the empty slot. Framing score shows the total out of five with a hint restating your tone, genre, and audience word count. Audience detail shows the word count of your reader description with a hint that either repeats the description or asks for at least two words. Pairing line shows your anchor-meets-twist line, trimmed with an ellipsis only if it runs past forty characters, with the longer reader line as its hint.
The positioning map is a three-row table. The anchor row pairs your first title with a reader line shaped as for readers of your anchor who like your tone and genre. The twist row pairs your second title with a line about its pull on your book. The shelf row combines your genre and audience into a single placement sentence. Read the three rows top to bottom before you copy anything: anchor orients, twist qualifies, shelf summarizes.
The freshness checklist shows four items with pass-or-fail states. Two comps entered, comps differ, audience names a specific reader, and genre-plus-tone set. Each item carries a note with your actual entries or the precise repair. The recommendations block then turns those states into phrasing: the exact sentences to carry into a query draft, adjusted for whether slots are empty, duplicated, single, or complete.
The three phrasing templates, explained
The tool fills three sentence shapes from your inputs, and each shape serves a different slot in your pitch materials. Learn what each one is for before you paste them anywhere.
The pairing line joins your two titles with the word meets. The Night Shift meets Harbor Light is the pattern. This line belongs in conversation, in the opening or closing paragraph of a query, and anywhere you get one breath to place the book. Its strength is speed: two known titles side by side create a combined expectation instantly. Its weakness is that it explains nothing by itself, so it must always be followed by one sentence about what your book changes. Never send the pairing line alone.
The reader line starts with for readers of and names your anchor, then appends your tone and genre. For readers of The Night Shift who like dark thrillers is the pattern. This line belongs at the top of a query or at the start of back-cover thinking, because it names the buyer before it names the book. Its strength is that it flatters the reader's existing taste instead of lecturing about craft. Its weakness is vagueness if the anchor is too famous, so the follow-up sentence must narrow with plot specifics.
The shelf line combines genre, audience, and twist pull in one statement. Thriller for adult thriller readers, with the dark pull of Harbor Light is the pattern. This line belongs in positioning discussions with yourself, in category selection on retail platforms, and in newsletter or ad audience notes. Its strength is completeness: shelf, buyer, and flavor in a single clause. Its weakness is stiffness, so loosen the wording when it moves into actual cover copy or ad text.
All three lines are assembled, not written, by the tool. The tool inserts your exact title spellings, your selected tone word, your selected genre label, and your audience phrase into fixed shapes. If a line reads awkwardly, the repair is in your inputs: shorten an overlong title entry, sharpen a vague audience, or reconsider a tone word that fights your genre. The shapes never change, so every improvement to an input improves all three lines at once.
The positioning map, row by row
The anchor row answers the question of where a stranger should start. Your first title should be the most recognizable book your actual readers have read. Recognition matters more than prestige here. An anchor that ten thousand of your buyers know beats an anchor that ten million strangers know but your buyers never picked up. When you test candidate anchors, ask which title your reader would nod at fastest, not which title would impress an observer.
The twist row answers the question of what turns your book aside from that start. Your second title should share the genre neighborhood yet differ in plot engine, relationship stakes, structure, or setting pressure. If the anchor is a lone-investigator procedural, the twist might carry a family-secret engine or a two-timeline structure. The difference between the two titles is the most informative part of the whole map, because it sketches the space your book occupies without describing a single scene.
The shelf row answers the question of who buys and where it sits. Genre plus audience is a retail fact, not a boast. Thriller for adult thriller readers tells a bookseller which table and a marketer which mailing list. Writers sometimes resist this row as reductive, but reduction is its function. A buyer deciding in seconds needs the category before the nuance, and the shelf row delivers the category in plain words.
The freshness checklist, item by item
Two comps entered is the foundation check. An empty slot means the pairing line contains a placeholder instead of a title, and a placeholder cannot orient anyone. If you are stuck on the second slot, list five books your readers buy after finishing books like yours, then pick the one whose engine differs most from your anchor. That difference is doing real work in the framing.
Comps differ is the integrity check. Identical entries collapse the pair into a single signal, and near-identical entries nearly do the same. Test candidate pairs by finishing this sentence for each title separately: readers come to this book for its distinctive engine and stakes. If both completions sound the same, replace one candidate. The pair should complete that sentence two different ways.
Audience names a specific reader is the targeting check. One word, such as readers or adults, fits millions of people and therefore guides nobody. Two or more words force a choice: adult thriller readers, cozy mystery fans over forty, new-adult romantasy readers. Each added precise word removes the wrong buyers and keeps the right ones. Count the words, keep at least two, and prefer words that describe buying behavior over vague praise.
Genre and tone set is the standing check. It always passes in this tool because the form always holds a selection, but its presence in the checklist reminds you that the pairing lines key off those two words. If your lines feel wrong, revisit the selections before you blame the titles. A hopeful pick on a bleak book, or a thriller pick on a slow family story, will bend every generated line away from the truth.
Illustrative hypothetical example one: a dark thriller with a full pair
This example is entirely illustrative and hypothetical, with invented titles and numbers used only to show the mechanics. Imagine a writer named Dana who has finished a 85,000-word thriller about a night-shift dispatcher who hears a call that never gets logged. Dana picks thriller as genre and dark as tone, types adult thriller readers as the audience, enters The Night Shift as the anchor and Harbor Light as the twist.
The tool counts 2 of 2 comps. The lowercase comparison finds two different strings, so distinctness passes. The audience splits into 3 words, so specificity passes. Genre-plus-tone adds the fifth point. Framing score reads 5 of 5 and the verdict passes. The pairing line reads The Night Shift meets Harbor Light. The reader line reads for readers of The Night Shift who like dark thrillers. The shelf line reads thriller for adult thriller readers, with the dark pull of Harbor Light.
Dana's next move is the sentence the tool cannot write for her. She drafts one line about what her book changes: the dispatcher cannot go to the police because the missing call implicates her own brother. That sentence follows the pairing line in her query draft. The comps orient, her sentence differentiates, and the paragraph is done. Total query real estate spent on comps: two titles and one follow-up sentence. Everything else in the letter covers her plot, her stakes, and her word count.
Hypothetical example two: a hopeful romance with a missing twist
This second example is also hypothetical, with invented titles standing in for whatever real books a writer might use. Imagine a writer named Priya with a 78,000-word romance about two rival food-truck owners forced to share a winter lot. Priya picks romance as genre and hopeful as tone, types adult romance readers as the audience, enters Summer Letters as the anchor, and leaves the second slot blank.
The tool counts 1 of 2 comps. Distinctness cannot pass with one entry. The audience counts 3 words and passes. Genre-plus-tone passes. The framing score is 3 of 5 and the verdict warns that the twist slot is empty. The positioning map still renders, but the twist row and the pairing line carry a placeholder where the second title should be, which shows Priya exactly what a reader would feel: half oriented, half waiting.
Priya repairs the gap from the reader side. She lists what her buyers read after finishing books like Summer Letters and notices many pick up workplace rivalries with shared-stakes endings. She chooses a second title from that shelf whose engine is the forced-proximity partnership rather than letters across distance. Once both slots hold different titles, the score rises to 5 of 5. Her pairing line now promises the familiar warmth plus the specific rivalry engine, and her follow-up sentence names the winter lot that forces the pair together.
Genre-specific guidance
Thriller comps should name the engine first. Readers of this shelf buy pace, pressure, and reversal, so your anchor should be a book whose momentum your readers recognize, and your twist should name a different pressure source. A conspiracy anchor beside a domestic-suspense twist tells the listener that your stakes are personal rather than institutional. Keep the audience phrase concrete, such as adult thriller readers or domestic suspense readers, and let the tone word, often dark or gritty, set the temperature.
Mystery comps should separate the detective shape from the puzzle shape. An amateur-sleuth anchor beside a police-procedural twist confuses the promise, because those sub-shelves buy different things. Match the investigation structure across your pair: cozy with cozy, procedural with procedural, then let the twist differ in setting pressure or secret type. Audiences like cozy mystery readers or Nordic noir readers carry real shelving information, so write them precisely.
Romance comps must name the relationship engine and the ending temperature. A grumpy-sunshine anchor beside a second-chance twist promises two different pleasures unless your book truly contains both. Better to pair two titles that share the trope family and differ in setting or stakes scale. Hopeful and romantic are the tones that fit most of this shelf; use funny only when the banter truly drives the book, because mislabeled humor disappoints fast.
Fantasy comps should split the world from the plot. Readers ask what kind of magic system, what scale of conflict, and how the book handles power. Your anchor can carry the world feel while your twist carries the plot shape, such as a quest anchor beside a court-intrigue twist. Gritty suits low-magic brutal shelves, hopeful suits coming-of-power arcs. Name audiences like adult epic fantasy readers or young-adult romantasy readers with care, since age category changes everything about comparable placement.
Science fiction comps should separate the technology question from the story shape. A first-contact anchor beside a generation-ship twist promises different wonders. Decide whether your book sells the idea or the crew: idea-driven anchors attract readers who want speculation, crew-driven twists attract readers who want relationships under pressure. Dark fits dystopian pressure, hopeful fits exploration wonder. Audience phrases like adult space-opera readers or near-future science fiction readers do genuine filtering work.
Horror comps must be honest about fear type and intensity. A haunted-house anchor beside a folk-horror twist tells the reader which dread to expect. Do not soften the tone word here to chase a wider audience; a dark or gritty label that matches the manuscript builds the right readership, while hopeful on a bleak book breeds resentful reviews. Audiences like horror readers who like slow-burn dread are worth the extra words because sub-shelf matters enormously.
Literary fiction comps should name the attention contract. These readers buy voice, sentence texture, and interior depth, so your anchor should be a book whose prose patience your readers share, and your twist should name the structural or thematic turn. A multigenerational anchor beside a single-day compressed twist signals form as well as feeling. Tone words carry unusual weight on this shelf: hopeful against dark is a real fork in readership, so choose by the book's ending temperature and dominant weather, not by aspiration.
Edge cases and failure modes
The most common failure is comping books you have not read. Borrowed comps collapse under the first follow-up question, whether from an agent, an editor, or a reader at a signing table. If someone asks what your book takes from the twist title and you cannot answer in specifics, the pairing reads as decoration. Read both comps fully before you commit, and be ready to name one craft element each contributes: pacing, structure, point of view, secret handling, or relationship rhythm.
The second failure is pairing two titles at wildly different scales without acknowledging it. A mega-phenomenon anchor is acceptable as orientation, but when both comps are once-a-decade giants, the promise sounds inflated. Balance one wide anchor with one closer, recent, same-scale twist. The tool cannot verify fame or sales, so this judgment stays entirely with you: ask whether a skeptical agent would find the scale of your pair credible for a debut in your lane.
The third failure is the echo pair. Two titles by the same author, two installments of one series, or two books with the same engine and stakes send one signal twice. The distinctness check catches exact duplicates, but near-duplicates pass the arithmetic while failing the purpose. Apply the sentence test from the checklist section: if both titles complete the readers-come-for sentence identically, swap one out.
The fourth failure is audience drift. A thriller manuscript framed for adult thriller readers while the query letter courts young-adult crossover splits every downstream decision, from cover to category to ad targeting. Keep the audience phrase in this tool identical to the audience phrase in your query materials. One reader, named the same way everywhere, beats three plausible readers named three different ways.
The fifth failure is tone mismatch. Writers sometimes pick a tone word for the book they wish they had written. If beta readers describe your manuscript as bleak and your tool inputs say hopeful, every generated line will mislead. Collect three reader descriptions of your book's feeling before you set the tone selection, and go with the majority report over your aspiration.
The sixth failure is placeholder comps shipped into real queries. The tool renders placeholder text when a slot is empty so you can preview the shapes, and that preview text must never be sent anywhere. Treat any output containing a placeholder as a draft state. Fill both slots with real published titles before the lines leave your desk.
The seventh failure is letting comps do characterization work they cannot do. A pairing line cannot establish your protagonist, your central choice, or your ending temperature. If your query draft leans on the comps for more than one paragraph, rebalance: one pairing line plus one differentiation sentence, then plot, stakes, and word count in your own words. Comps open the door; your story must walk through it.
Questions writers ask, answered in depth
How recent should comps be. Prefer at least one title from the last several years, because recent comps prove you read the current shelf and understand today's buyer. An anchor older than a decade can still orient, especially when its premise is famous, but it should sit beside a newer twist that shows present awareness. The tool does not check publication dates, so track recency yourself with a simple rule: one timeless orienter plus one current neighbor.
Whether comps must match your exact subgenre. They should sit close enough that a buyer of those titles would plausibly buy yours. A thriller writer comping space opera confuses every downstream choice. A domestic-suspense writer comping a police procedural strains the promise. Near-neighbor comps with one clear shared engine and one clear difference outperform distant prestige comps every time.
Whether to comp books by authors you know personally. Friendship is not positioning. If the friend's book genuinely shares your shelf, engine, and readership, it can serve, but the comp must survive the same tests as any other: recognizable to your buyers, honestly read by you, and different from your other comp. When in doubt, pick the title your readers know best rather than the author you know best.
How to handle comps when switching genres. Writers moving shelves should comp the destination, not the origin. Your new book's buyers live on the new shelf, and comps from your old shelf drag the wrong expectations along. If your name carries history on another shelf, address that in your author paragraph, not in the comp line.
What to do when your book blends two genres. Pick the shelf you will actually publish into: the category you will select at upload, the table a bookseller would use, the mailing list you will mail. Comp both titles from that shelf, then let one twist title gesture at the blend. A blended book shelved decisively outsells a blended book shelved twice.
How to talk about comps in person. Say the pairing line, then the differentiation sentence, then stop. Pitch settings reward brevity, and over-explaining either comp sounds defensive. If the listener lights up at the anchor, expand on your twist. If they frown, ask what they read recently and adjust the anchor next time. Live feedback is the fastest comp education available.
How often to revisit comps. Revisit whenever the manuscript changes shape in revision, and revisit on a calendar rhythm as your shelf moves. A twist that fit draft two may no longer fit draft five after you changed the ending. A pair that felt current three years ago may now read dated. Ten minutes with this tool after each major revision keeps the framing honest.
Doing the work inside Co-Writer
Planning comps is fast, but earning them takes a manuscript whose engine and stakes match the promise. Co-Writer at slash write is the place to do that drafting and revision work, with your pairing lines pinned beside the chapters they describe. Draft the scenes that deliver the anchor's familiar pleasure and the twist's distinct turn in that workspace until the framing lines read true.